As of early fall 2016 registered Democrats outnumber Republicans by 919,000 in Pennsylvania, with 4.1 million Democrats and 3.2 million Republicans.  452,669 voters were registered with non-major parties and 702,482 defined themselves as non-affiliated.  The gap between the number of registered Democrats and the number of registered Republicans in the state has drastically decreased in recent years.
The table also indicates the historical party composition in the:
- State Senate
- State House of Representatives
- State delegation to the United States Senate
- State delegation to the United States House of Representatives
Pennsylvania currently has 20 electoral votes based on their 18 seats in the United States House of Representatives and 2 United States Senators. The table below indicates which party's nominees received the state's electoral votes for the years in which a presidential election was held.
The parties are as follows: Anti-Administration (AA); Anti-Masonic (AM); Democratic (D); Democratic-Republican (DR); Federalist (F); Jacksonian (J); (N), or unknown; no partyNational Union (NU); National Republican (NR); Opposition (O); (PA); Pro-AdministrationProgressive (P); Republican (R); Whig (W); and . a tie or coalition within a group of elected officials
|Year||Executive offices||State Legislature||United States Congress||Electoral College votes|
|Governor||Lieutenant Governor||Attorney General||Auditor||Treasurer||State Senate||State House||U.S. Senator (Class I)||U.S. Senator (Class III)||U.S. House|
|1777||||||||David Rittenhouse||51Con, 15Rep, 6?||began in 1789|
|1778||54Con, 7?, 5Rep|
|1779||43Con, 26Rep, 3?|
|1780||51Con, 14Rep, 7?|
|1783||39Rep, 34Con, 1?|
|1789||Christian Febiger||47Rep, 22Con||William Maclay (AA)||Robert Morris (PA)||6PA, 2AA||George Washington (N) and John Adams (F)|
|1791||Thomas Mifflin (F)||||10F, 8DR||36F, 33DR||vacant||4PA, 4AA|
|1793||9F, 9DR ||8AA, 5PA|
|1794||10F, 8DR||48F, 21DR||Albert Gallatin (AA)|
|1795||14F, 10DR||49F, 29DR||William Bingham (F)||8DR, 5F|
|1796||15F, 9DR||45F, 33DR||7DR, 6F||Thomas Jefferson (DR) N and John Adams (F) N|
|1797||Peter Baynton||44F, 34DR||James Ross (F)||8DR, 5F|
|1799||47F, 31DR||9DR, 4F|
|1800||Thomas McKean (DR)||16F, 8DR||41DR, 37F||Thomas Jefferson (DR) Nand John Adams (F)|
|1801||Jacob Carpenter||13F, 11DR||55DR, 23F||Peter Muhlenberg (DR)||10DR, 3F|
|George Logan (DR)|
|1802||Isaac Weaver||17DR, 8F||71DR, 15F|
|1803||21DR, 4F||77DR, 9F||Samuel Maclay (DR)||18DR|
|1804||24DR, 1F||81DR, 5F||Thomas Jefferson and George Clinton (DR)|
|1805||25DR||78DR, 8F||17DR, 1F|
|1806||15 Const., 10DR ||53 Const., 33DR |
|1807||William Findlay (DR)||13 Const., 12DR ||46DR, 40 Const. ||Andrew Gregg (DR)||15DR, 3F|
|1808||14DR, 7 Quid, 4F||43DR, 23F, 20 Quid ||James Madison and George Clinton (DR)|
|1809||Simon Snyder (DR)||19DR, 7 Quid, 5F||74DR, 21F||Michael Leib (DR)||16DR, 2F|
|1810||22DR, 6F, 3 Quid||73DR, 15F, 7 Quid|
|1811||21DR, 7F, 2 Old School R, 1 Quid||72DR, 17F, 6 Quid||17DR, 1F|
|1812||26DR, 5F||84DR, 11F||James Madison and Elbridge Gerry (DR)|
|1813||77DR, 18F||Abner Lacock (DR)||22DR, 1F|
|1814||25DR, 6F||85DR, 10F||21DR, 2F|
|1815||21DR, 10F||71DR, 24F||Jonathan Roberts (DR)||19DR, 4F|
|1816||19DR, 12F||71DR, 26F||James Monroe and Daniel D. Tompkins (DR)|
|1817||R. M. Crain||57DR, 30F, 10 Old School R|
|1818||William Findlay (DR)||55DR, 42F |
|1819||20DR, 11F||64DR, 33F||Walter Lowrie (DR)|
|1820||John B. Trevor||23DR, 6F, 2 Old School R||67DR, 24F, 6 Old School R||18DR, 5F|
|1821||Joseph Hiester (DR)||William Clark||20DR, 11F||52F, 45DR||vacant||15DR, 8F|
|1822||17DR, 14F||67DR, 30F||William Findlay (DR)||16DR, 7F|
|1823||23DR, 10F||71DR, 29F||20DR, 6F|
|1824||John Andrew Shulze (DR)||21DR, 11F, 1?||77DR, 23F||Andrew Jackson and John C. Calhoun (DR) N|
|1825||26DR, 7F||79DR, 21F||William Marks (NR)||14J, 11DR, 1F|
|1826||27DR, 6F||77DR, 23F||17J, 9DR|
|1827||Alexander Mahon||74DR, 26F||Isaac D. Barnard (J)||22J, 3DR, 1NR|
|1828||26J, 7NR||76J, 22NR, 2 vac.||Andrew Jackson and John C. Calhoun (D)|
|1829||89J, 11NR||24J, 1AM, 1NR|
|1830||George Wolf (J)||26J, 6NR, 1AM||87J, 13AM|
|1831||25J, 5NR, 4AM||72J, 28AM||William Wilkins (J)||17J, 7AM, 2NR|
|1832||23J, 6AM, 4NR||74J, 22AM, 4NR||George M. Dallas (J)||Andrew Jackson and Martin Van Buren (D)|
|1833||22J, 9AM, 2NR||61J, 33AM, 5NR, 1?||Samuel McKean (J)||14J, 10AM, 4NR|
|1834||24J, 7AM, 2NR||64J, 25AM, 11NR|
|1835||Joseph Lawrence||25J, 6AM, 2W||62J, 27AM, 11W||17J, 7AM, 4NR|
|1836||Joseph Ritner (AM)||Daniel Sturgeon (D)||23D, 9AM, 1W||72AM/W, 28D||Martin Van Buren and Richard Mentor Johnson (D)|
|1837||15D, 12W, 6A-M ||72D, 21A-M, 7W||James Buchanan (D)||16D, 7AM, 3W, 2J|
|1838||19W, 14D||56D, 44W|
|1839||David R. Porter (D)||18W, 15D||vacant||17D, 6W, 5AM|
|1840||Almon H. Reed||17D, 16W||69D, 31W||William Henry Harrison and John Tyler (W)|
|1841||John Gilmore (D)||20W, 13D||55W, 45D||15D, 13W|
|1842||Job Mann (D)||17W, 16D||64D, 34W, 2 Wkngmn|
|1843||19D, 14W||57D, 40W, 2 Wkngmn, 1I||12D, 12W|
|1844||22D, 11W||58D, 42W||13W, 11D||James K. Polk and George M. Dallas (D)|
|1845||Francis R. Shunk (D)||James Ross Snowden||21D, 11W, 1A||51D, 41W, 8A||Daniel Sturgeon (D)||Simon Cameron (D)||12D, 10W, 2 A|
|1846||18W, 14D, 1A||67D, 33W|
|1847||John Banks||56W, 44D||16W, 7D, 1A|
|1848||Arnold Plumber||19W, 14D||64D, 36W||15W, 8D, 1A||Zachary Taylor and Millard Fillmore (W)|
|William F. Johnston (W)|
|1849||Gideon J. Ball||21W, 12D||50D, 45W, 5A ||James Cooper (W)||11W, 11D, 1A, 1 FS|
|1850||John M. Bickel||vacant||17D, 16W||59D, 41W|
|1851||Ephraim Banks||16W, 16D, 1I ||60D, 36W, 2ID, 1IW, 1 vac.||Richard Brodhead (D)||15D, 9W|
|1852||William Bigler (D)||17W, 16D||58D, 37W, 5A||Franklin Pierce and William R. King (D)|
|1853||17W, 15D, 1A||62D, 38W||16D, 9W|
|1854||Joseph Bailey (D)||18D, 14W, 1A||70D, 26W, 4A|
|1855||James Pollock (W)||Eli Slifer||17D, 15W, 1A||46W, 32D, 22A ||vacant||13O, 7D, 3W, 1R, 1A|
|1856||Henry S. Magraw||17D, 16 Fus.||66D, 34 Fus.||William Bigler (D)||James Buchanan and John C. Breckinridge (D)|
|1857||Jacob Fryle, Jr.||18 Fus., 15D||53D, 47 Fus.||Simon Cameron (R)||15D, 10R|
|1858||William F. Packer (D)||21D, 12R||68D, 30R, 2I||14D, 11R|
|1859||Eli Slifer||17D, 16R||67R, 33D||20R, 5D|
|1860||Thomas E. Cochran||21R, 12D||66R, 34D||Abraham Lincoln and Hannibal Hamlin (R)|
|1861||Andrew Gregg Curtin (R)||Henry Dunning Moore (R)||27R, 6D||71R, 29D||David Wilmot (R)||Edgar Cowan (R)||19R, 6D|
|1862||23R, 10D||51D, 49R||17R, 8D|
|1863||Isaac Slenker||William V. McGrath||21R, 12D||55D, 45R||Charles R. Buckalew (D)||12R, 12D|
|1864||Henry Dunning Moore (R)||17R, 16D||52R, 48D||Abraham Lincoln and Andrew Johnson (NU)|
|1865||William H. Kemble||20R, 13D||64R, 36D||15R, 9D|
|1866||John F. Hartranft (R)||21R, 12D||67R, 33D||16R, 8D|
|1867||John W. Geary (R)||62R, 38D||Simon Cameron (R)||18R, 6D|
|1868||W. W. Irwin||19R, 14D||54R, 46D||Ulysses S. Grant and Schuyler Colfax (R)|
|1869||Robert W. Mackey||18R, 15D||62R, 38D||John Scott (R)||16R, 8D|
|1870||W. W. Irwin||60R, 40D||18R, 6D|
|1871||Robert W. Mackey||17D, 16R||55R, 45D||13R, 11D|
|1872||17R, 16D||63R, 39D, 1I||Ulysses S. Grant and Henry Wilson (R)|
|C. D. Brigham|
|Harrison Allen (R)|
|1873||John F. Hartranft (R)||18R, 14D, 1LR||60R, 39D, 1I||22R, 5D|
|1874||20R, 12D, 1LR||57R, 43D|
|1875||John Latta (D)||Justus F. Temple||30R, 20D ||110D, 89R, 1I, 1 Proh. ||William A. Wallace (D)||17D, 10R|
|1876||Henry Rawle||29R, 21D||18D, 9R||Rutherford B. Hayes and William A. Wheeler (R)|
|1877||31R, 19D||119R, 81D, 1ID||17R, 10D|
|1878||William P. Schell||Amos C. Noyes|
|1879||Henry M. Hoyt (R)||Charles Warren Stone (R)||32R, 17D, 1GB||107R, 77D, 17GB||17R, 8D, 2 GB|
|1880||Samuel Butler||James A. Garfield and Chester A. Arthur (R)|
|1881||John A. Lemon||121R, 78D, 1GB, 1 Fus. Dem.||John I. Mitchell (R)||18R, 7D, 2GB|
|1882||Silas M. Bailey|
|1883||Robert E. Pattison (D)||Chauncey Forward Black (D)||30R, 20D||113D, 88R||15R, 12D, 1GB|
|1884||Jerome B. Niles||William Livsey||James G. Blaine and John A. Logan (R) N|
|1885||31R, 19D||140R, 60D, 1GBR||James Donald Cameron (R)||20R, 8D|
|1886||Matthew S. Quay (R)|
|1887||James A. Beaver (R)||William T. Davies (R)||A. Wilson Norris ||William Livsey||34R, 16D||131R, 69D, 1GBL||Matthew S. Quay (R)|
|1888||William B. Hart||Benjamin Harrison and Levi P. Morton (R)|
|1889||William Livsey||144R, 60D||21 R, 7D|
|1890||Henry K. Boyer|
|1891||Robert E. Pattison (D)||Louis Arthur Watres (R)||31R, 19D||122R, 79D, 3 Fus.||18R, 10D|
|1892||David McMurtrie Gregg (R)||John W. Morrison||17R, 11D||Benjamin Harrison and Whitelaw Reid (R) N|
|1893||33R, 17D||135R, 69D||20R, 10D|
|1894||Samuel M. Jackson|
|1895||Daniel H. Hastings (R)||Walter Lyon (R)||Amos H. Mylin||44R, 6D||175R, 29D||28R, 2D|
|1896||Benjamin J. Haywood||William McKinley and Garret Hobart (R)|
|1897||172R, 32D||Boies Penrose  (R)||27R, 3D|
|1898||Levi G. McCauley (R)||James S. Beacom (R)|
|1899||William A. Stone (R)||John P. S. Gobin (R)||37R, 13D||127R, 71D, 6 Fus.||vacant||20R, 10D|
|1900||James E. Barnett (R)||William McKinley and Theodore Roosevelt (R)|
|1901||Edmund B. Hardenbergh (R)||38R, 12D||156R, 48D||Matthew S. Quay (R)||26R, 4D|
|1902||Frank G. Harris (R)|
|1903||Samuel W. Pennypacker (R)||William M. Brown (R)||40R, 10D||160R, 44D||28R, 4D|
|1904||William P. Snyder (R)||William L. Mathues (R)||29R, 3D||Theodore Roosevelt and Charles W. Fairbanks (R)|
|Philander C. Knox (R)|
|1905||187R, 17D||31R, 1D|
|1906||William H. Berry (D)|
|1907||Edwin Sydney Stuart (R)||Robert S. Murphy (R)||Robert K. Young (R)||157R, 50D||25R, 7D|
|1908||John O. Sheatz (R)||William Howard Taft and James S. Sherman (R)|
|1909||39R, 11D||173R, 34D||George T. Oliver (R)||27R, 5D|
|1910||A.E. Sisson (R)|
|1911||John K. Tener (R)||John Merriman Reynolds (R)||Charles Frederick Wright (R)||38R, 18D||162R, 44D, 1S||23R, 9D|
|1912||24R, 8D||Theodore Roosevelt and Hiram Johnson (P) N|
|1913||Archibald W. Powell (R)||Robert K. Young (R)||34R, 13D, 3P||127R, 57D, 14P, 9 Wash.||22R, 12D, 2P|
|1915||Martin Grove Brumbaugh (R)||Frank B. McClain (R)||38R, 11D, 1P||164R, 41D, 1S, 1P||30R, 6D|
|1916||Charles Evans Hughes and Charles W. Fairbanks (R) N|
|1917||Charles A. Snyder (R)||Harmon M. Kephart (R)||39R, 10D, 1P||169R, 37D, 1S, 1P||Philander C. Knox (R)||29R, 6D, 1P|
|1918||28R, 7D, 1P|
|1919||William Cameron Sproul (R)||Edward E. Beidleman (R)||44R, 6D||184R, 23D||29R, 7D|
|1920||30R, 6D||Warren G. Harding and Calvin Coolidge (R)|
|1921||Samuel S. Lewis (R)||Charles A. Snyder (R)||47R, 3D||193R, 14D||35R, 1D|
|William E. Crow (R)|
|1922||George Wharton Pepper (R)|
|David A. Reed (R)|
|1923||Gifford Pinchot (R)||David J. Davis (R)||43R, 7D||167R, 41D||30R, 6D|
|1924||Calvin Coolidge and Charles G. Dawes (R)|
|1925||Edward Martin (R)||Samuel S. Lewis (R)||42R, 8D||194R, 14D||36R|
|1927||John Stuchell Fisher (R)||Arthur James (R)||45R, 5D||191R, 17D||William Scott Vare (R)||34R, 2D|
|1928||Herbert Hoover and Charles Curtis (R)|
|1929||Charles A. Waters (R)||Edward Martin (R)||44R, 6D||192R, 16D||35R, 1D|
|1930||Joseph R. Grundy (R)||36R|
|1931||Gifford Pinchot (R)||Edward C. Shannon (R)||46R, 4D||184R, 22D, 2S||James J. Davis (R)||33R, 3D|
|1932||Herbert Hoover and Charles Curtis (R) N|
|1933||Frank E. Baldwin (R)||Charles A. Waters (R)||43R, 7D||140R, 65D, 2I, 1S||23R, 11D|
|1935||George Howard Earle III (D)||Thomas Kennedy (D)||31R, 19D||117D, 89R, 2S||Joseph F. Guffey (D)||23D, 11R|
|1936||Franklin D. Roosevelt and John Nance Garner (D)|
|1937||Warren R. Roberts (D)||F. Clair Ross (D)||34D, 16R||154D, 54R||27D, 7R|
|1939||Arthur James (R)||Samuel S. Lewis (R)||27R, 23D||129R, 79D||19R, 15D|
|1940||Franklin D. Roosevelt and Henry A. Wallace (D)|
|1941||F. Clair Ross (D)||G. Howard Wagner (R)||32R, 18D||126D, 82R||19D, 15R|
|1943||Edward Martin (R)||John C. Bell, Jr. (R)||132R, 76D||20R, 13D|
|1944||21R, 12D||Franklin D. Roosevelt and Harry S. Truman|
|1945||Ted A. Rosenberg||Ramsey S. Black (D)||109R, 99D||Francis J. Myers (D)||18R, 15D|
|G. Howard Wagner (R)|
|1947||John C. Bell, Jr. (R)||vacant||34R, 16D||170R, 38D||Edward Martin (R)||28R, 5D|
|James H. Duff (R)||Daniel B. Strickler (R)|
|1948||Thomas E. Dewey and Earl Warren (R) N|
|1949||Weldon B. Heyburn (R)||Charles R. Barber (R)||35R, 15D||117R, 91D||17R, 16D|
|1951||John S. Fine (R)||Lloyd H. Wood (R)||30R, 20D||120R, 88D||James H. Duff (R)||20R, 13D|
|1952||Dwight D. Eisenhower and Richard Nixon (R)|
|1953||Charles R. Barber (R)||Weldon B. Heyburn (R)||32R, 18D||110R, 98D||19R, 11D |
|1955||George M. Leader (D)||Roy E. Furman (D)||26R, 24D||112D, 98R||16R, 14D|
|1957||Charles C. Smith (R)||Robert F. Kent (R)||27R, 23D||126R, 84D||Joseph S. Clark (D)||17R, 13D|
|1959||David L. Lawrence (D)||John Morgan Davis (D)||28R, 22D||108D, 102R||Hugh Scott (R)||16D, 14R|
|1960||John F. Kennedy and Lyndon B. Johnson (D)|
|1961||Thomas Z. Minehart (D)||Grace M. Sloan (D)||25D, 25R ||109D, 101R||16R, 14D|
|1963||William Scranton (R)||Raymond P. Shafer (R)||27R, 23D||108R, 102D||14R, 13D |
|1964||Lyndon B. Johnson and Hubert Humphrey (D)|
|1965||Grace M. Sloan (D)||Thomas Z. Minehart (D)||28R, 22D||116D, 93R||15D, 12R|
|1967||Raymond P. Shafer (R)||Raymond J. Broderick (R)||27R, 23D||104R, 99D||14D, 13R|
|1968||Hubert Humphrey and Edmund Muskie (D) N|
|1969||Bob Casey Sr. (D)||Grace M. Sloan (D)||107D, 96R||Richard S. Schweiker (R)|
|1971||Milton Shapp (D)||Ernest P. Kline (D)||26D, 24R||113D, 90R|
|1972||Richard Nixon and Spiro Agnew (R)|
|1973||107R, 96D||13D, 12R |
|1975||30D, 20R||113D, 90R||14D, 11R|
|1976||Jimmy Carter and Walter Mondale (R)|
|1977||Al Benedict (D)||Robert E. Casey (D)||31D, 19R||118D, 85R||John Heinz (R) ||17D, 8R|
|1979||Dick Thornburgh (R)||William Scranton, III (R)||28D, 22R||102R, 101D||15D, 10R|
|1980||Ronald Reagan and George H. W. Bush (R)|
|1981||LeRoy S. Zimmerman (R)||Budd Dwyer (R) ||26R, 24D||103R, 100D||Arlen Specter (R)||13D, 12R|
|1983||27R, 23D||103D, 100R||13D, 10R |
|1985||Donald A. Bailey (D)|
|1987||Bob Casey (D)||Mark Singel (D)||G. Davis Greene (D) ||26R, 24D||102D, 101R||12D, 11R|
|1988||George H. W. Bush and Dan Quayle (R)|
|1989||Ernie Preate (R) ||Barbara Hafer (R)||Catherine Baker Knoll (D)||27R, 23D||104D, 99R|
|1991||26R, 24D||107D, 96R||12R, 11D|
|Harris Wofford (D) |
|1992||Bill Clinton and Al Gore (D)|
|1993||25D, 25R ||105D, 98R||11D, 10R |
|1994||26R, 24D |
|1995||Tom Ridge (R)||Mark S. Schweiker (R)||29R, 21D||102R, 101D||Rick Santorum (R)|
|Tom Corbett (R) |
|1997||D. Michael Fisher (R) ||Bob Casey Jr. (D)||Barbara Hafer (R)||30R, 20D||104R, 99D|
|2000||Al Gore and Joe Lieberman (D) N|
|2001||104R, 99D||11R, 10D|
|Mark S. Schweiker (R) ||Robert Jubelirer (R) |
|2003||Ed Rendell (D)||Catherine Baker Knoll (D) ||Barbara Hafer (D)||29R, 21D||110R, 93D||12R, 7D |
|2004||John Kerry and John Edwards (D) N|
|Jerry Pappert (R) |
|2005||Tom Corbett (R)||Jack Wagner (D)||Bob Casey Jr. (D) ||30R, 20D||110R, 93D|
|2007||Robin Wiessmann (D) ||29R, 21D||102D, 101R ||Bob Casey Jr. (D)||11D, 8R|
|2008||Barack Obama and Joe Biden (D)|
|Joseph B. Scarnati (R) |
|2009||Robert McCord (D)  ||30R, 20D||104D, 99R||12D, 7R|
|Arlen Specter (D) |
|2011||Tom Corbett (R)||Jim Cawley (R)||Linda L. Kelly (R)  ||112R, 91D||Pat Toomey (R)||12R, 7D|
|2013||Kathleen Kane (D)  ||Eugene DePasquale (D)||27R, 23D||111R, 92D||13R, 5D |
|2015||Tom Wolf (D)||Mike Stack (D)||Tim Reese (I) ||30R, 20D||120R, 83D|
|2016||31R, 19D||119R, 84D||Donald Trump and Mike Pence (R)|
|Bruce Beemer (D)  |
|2017||Josh Shapiro (D)||Joe Torsella (D)||34R, 16D||122R, 82D|
|2018||10R, 6D, 2 vacant  |
|2019||John Fetterman (D)||29R, 21D||110R, 93D||9R, 9D|
|Year||Governor||Lieutenant Governor||Attorney General||Auditor||Treasurer||State Senate||State House||U.S. Senator (Class I)||U.S. Senator (Class III)||U.S. House||Electoral College votes|
|Executive offices||State Legislature||United States Congress|
- Democratic Party of Pennsylvania
- Elections in Pennsylvania
- Green Party of Pennsylvania
- Libertarian Party of Pennsylvania
- Politics of Pennsylvania
- Republican Party of Pennsylvania
- McKelvey, Wallace (September 9, 2016). "GOP Gaining Ground Against Dems in Pa. Voter Registration Race". Pennlive.com. PA Media Group. Retrieved October 8, 2016.
- "Current Voter Registration Statistics". Pennsylvania Department of State. Archived from the original on October 7, 2016. Retrieved October 8, 2016.
- From 1777–1790, Pennsylvania had a series of presidents and vice presidents of The Supreme Council.
- Not an elected office until 1980.
- Became an elected office in 1850.
- Office created in 1873 and first filled in 1875.
- A Federalist, Anthony Morris, was elected as Speaker of the chamber
- The Federalists and Quids, who were moderates within the Democratic-Republican Party, formed a coalition in the 1805 election and called themselves the Consititionalists; when they achieved a majority, they organized the chamber together, and this coalition continued in succeeding elections. 
- Elected Nathaniel Boileau, a Democratic-Republican, as Speaker.
- Some sources begin to cite the Federalists at the state level as Independent Republicans starting with this year.
- The Whigs and Anti-Masons formed a coalition to govern the chamber.
- A Democrat, William F. Packer, was elected as Speaker, and Democrats organized the chamber.
- A Whig, Benjamin Matthias, was elected as Speaker of the Senate on the 7th Ballot. p. 8-9
- A Whig, Henry K. Strong, was elected in a coalition between the Whigs and Know-Nothings.
- Effective with the Constitution of 1874, Senators began to serve four-year terms, after a transition period starting with the election of 1874 and continuing through the election of 1876.
- Effective with the Constitution of 1874, House members began to serve two-year terms starting with the election of 1874.
- Died in office.
- Districts 31, 32, and 33 eliminated in 1953.
- Due to the Democratic Lt. Governor casting the deciding vote, the Democrats took control of the chamber.
- Districts 28, 29, and 30 eliminated in 1963.
- Districts 26 and 27 eliminated in 1973.
- Districts 24 and 25 eliminated in 1983.
- Appointed to fill vacancy.
- Appointed by Governor Casey in May 1991 after Heinz's death and won a special election in November 1991 for the remainder of the term.
- Due to a party switch by Sen. Frank Pecora from Republican to Democrat, the Senate was split; in the case of ties, however, the Lt. Governor casts the deciding vote, and as a Democrat, he gave his party control. "Frank A Pecora". Pennsylvania General Assembly. Retrieved January 3, 2017.
- Districts 22 and 23 eliminated in 1993.
- After months of turmoil, a special election result was thrown out that had been won by Democrat William G. Stinson, who had succeeded fellow Democrat Francis Lynch. A federal judge awarded the election to Republican Bruce Marks. Additionally, Democrat Eugene Scanlon's death in March 1994 gave Republicans control. Eshleman Jr., Russell E. (March 11, 1994). "Pa. Sen. Scanlon Dies, Leaving Senate in Grief, GOP in Lead Regardless of the Stinson Outcome, the Republicans Are Now the Majority and Can Control the Action". Philadelphia Inquirer. p. B06. Archived from the original on January 3, 2016.
- As lieutenant governor, filled vacancy in office of governor.
- As president pro tempore of the state Senate, filled vacancy in office of lieutenant governor.
- Districts 20 and 21 eliminated in 2003.
- Resigned following election to U.S. Senate.
- Elected a Republican Speaker.
- Levy, Marc (January 31, 2015). "Pennsylvania treasurer Rob McCord says he will plead guilty to federal charges". Lancaster Online. Associated Press. Retrieved May 20, 2015.
- Switched parties from Republican to Democratic on April 28, 2009.
- William Ryan served as acting Attorney General from January (when Corbett was inaugurated as governor) until Kelly's nomination was confirmed by the State Senate.
- Pennsylvania Attorney General Kathleen Kane resigning
- District 19 eliminated in 2013.
- Republican Deputy Attorney General Bruce Castor served for 13 days from August 17–30 between Kane's resignation and Beemer's assumption of the office.
- Democrat Conor Lamb won a special election on March 13, 2018 to fill a vacancy for Pennsylvania's 18th Congressional District, left by Republican Timothy F. Murphy's resignation.
- Republicans Pat Meehan and Charlie Dent resigned in May 2018 and the seats remained vacant until special elections were held on November 6.