The Department of Homeland Security Office of Inspector General was established along with the Department of Homeland Security itself in 2002 by the Homeland Security Act. Its website describes its mission as "supervis[ing] independent audits, investigations, and inspections of the programs and operations of DHS, and recommends ways for DHS to carry out its responsibilities in the most effective, efficient, and economical manner possible." 
The United States Congress enacted the Inspector General Act of 1978 to ensure integrity and efficiency in government. The Homeland Security Act of 2002, as amended, established an Office of Inspector General (OIG) in the Department of Homeland Security (DHS). The Inspector General is appointed by the President and subject to Senate confirmation.
The Inspector General is responsible for conducting and supervising audits, investigations, and inspections relating to the programs and operations of the DHS. The OIG is to examine, evaluate and, where necessary, critique these operations and activities, recommending ways for the Department to carry out its responsibilities in the most effective, efficient, and economical manner possible.
To serve as an independent and objective inspection, audit, and investigative body to promote effectiveness, efficiency, and economy in the Department of Homeland Security's programs and operations, and to prevent and detect fraud, abuse, mismanagement, and waste in such programs and operations.
John Roth is the Inspector General. He was nominated by President Obama in November 2013 and confirmed by the Senate by voice vote in March 2014.  Roth previously oversaw the Food and Drug Administration's Office of Criminal Investigations and had a 25-year career that saw him serve as an assistant U.S. attorney, chief of staff to the deputy attorney general, and special counsel for international money laundering policy. 
The Department of Homeland Security’s first Senate confirmed Inspector General was Richard L. Skinner. Mr. Skinner retired on January 12, 2011.
Mr. Skinner had devoted forty-two years in his federal career to fulfilling the mission of the Inspectors General community. He began his career in 1969 with the Department of Agriculture, and held a variety of OIG management positions with the Departments of Justice, Commerce, State, and the Arms Controls and Disarmament Agency. He also served as the Acting Inspector General, Deputy Inspector General, and Assistant Inspector General for Audits at FEMA where he was awarded the President’s Meritorious Executive Rank Award for sustained superior accomplishment in management of programs of the United States Government. Prior to his July 28, 2005 confirmation, he held the position of Deputy Inspector General since March 1, 2003, the date that the Department of Homeland Security was created.
Mr. Skinner contributed to improved government services as the Recovery Accountability and Transparency Board Vice Chairman and Chair of the Board’s Accountability Committee. He was very active in the Council of the Inspectors General on Integrity and Efficiency where he chaired the Homeland Security Roundtable, and was Co-chairman of the National Procurement Fraud Task Force Legislative Committee. He was also a member of the CIGIE Integrity; Investigations; and Human Resources committees as well as the Interagency Coordination Group of Inspectors General for Guam Realignment and the Domestic Working Group. Official DHS / IG
Charles K. Edwards, who served as acting DHS inspector general from 2011 through 2013, resigned in December 2013 following allegations of abuse of power, withholding documents, misspending of funds, nepotism, and making his staff do his homework for his Ph.D.  It was also alleged that he routinely shared drinks and dinner with department leaders and gave them inside information about the timing and findings of investigations, according to the report from an oversight panel of the Homeland Security and Government Operations Committee. 
Claire McCaskill, chair of the FCO Subcommittee, stated in her report to the Senate: "The Subcommittee found that Mr. Edwards jeopardized the independence of the Office of the Inspector General and that he abused agency resources." 
- "What We Do". OIG website. Retrieved 21 March 2016.
- Leonnig, Carol D. (2014-04-24). "Probe: DHS watchdog cozy with officials, altered reports as he sought top job". Washington Post.
- "US Senate Subcommittee on Financial and Contracting Oversight". Retrieved 2014-04-24.