The Ortoiroid people were the second wave of human settlers of the Caribbean who began their migration into the Antilles around 2000 BCE   They were preceded by the Casimiroid peoples (~4190-2165 BCE). They are believed to have originated in the Orinoco valley in South America, migrating to the Antilles from Trinidad and Tobago to Puerto Rico. The name "Ortoiroid" comes from Ortoire, a shell midden site in southeast Trinidad. 
The two earliest Ortoiroid sites in Trinidad are the Banwari Trace and at St. John's Road, South Oropouche, which date back at least to 5500 BCE.  At this time, Trinidad might have still been connected to the South American mainland.
The majority of archaeological sites associated with the Ortoiroid are found near or on the coasts.  Tobago has at least one Ortoiroid site, Martinique has two, and Antigua has 24 Ortoiroid shell-midden sites. Ortoiroid peoples settled on St. Kitts from 2000 BCE to 400 BCE. 
In the north, two distinct Ortoiroid subcultures have been identified: the Coroso culture, which flourished from 1500 BCE–200 CE, and the Krum Bay culture, which spanned 1500—200 BCE. The Coroso people lived in Puerto Rico, where the oldest known site is the Angostura site, dating from 4000 BCE.  The Krum Bay people lived in the Virgin Islands.  Krum Bay culture, which emerged between 800 BCE and 225 BCE, also extended to St. Thomas. 
The Ortoiroid are considered the first settlers of the archipelago of Puerto Rico;  however, recent reexamination of date, artifact, and agricultural evidence and of assumptions about culture has suggested a more complex picture.[ clarification needed] 
Ortoiroid peoples were hunter-gatherers.  Shellfish remains have been found in these sites indicating that they constituted an important part of the Ortoiroid diet. They also ate turtles, crabs, and fish. 
They were known for their lithic technology but did not have ceramics.  Ortoiroid artifacts include bone spearpoints, perforated animal teeth worn as jewelry, and stone tools, such as manos and metates, net sinkers, pestles, choppers, hammerstones, and pebbles used for grinding. 
- Granberry, Julian & Vescelius, Gary. Languagues of the Pre-Columbian Antilles. The University of Alabama Press 2004. pp 39-40.
- Rouse, Irving. The Tainos: Rise & Decline of the People who Greeted Columbus. Yale University Press 1992. p. 81.
- Saunders 211
- Rouse 63.
- Saunders 13.
- Rouse 69.
- Saunders 260.
- "Prehistory of the Caribbean Culture Area." Southeast Archaeological Center (retrieved 9 July 2011).
- Saunders 264.
- Rodríguez Ramos 17, 54.
- "Rewriting History: There were people before the Caribs and Arawaks ." Archived 2012-03-14 at the Wayback Machine. Trinidad and Tobago Express via Archaeology Daily News. 4 February 2010 (retrieved 9 July 2011).
- Rodríguez Ramos, Reniel. Rethinking Puerto Rican Precolonial History. Tuscaloosa: University of Alabama Press, 2010. ISBN 978-0-8173-8327-5.
- Rouse, Irving. The Tainos: Rise and Decline of the People who greeted Columbus. New Haven, CT: Yale University Press, 1992. ISBN 978-0-300-05181-0.
- Saunders, Nicholas J. The Peoples of the Caribbean: an Encyclopedia of Archeology and Traditional Culture. ABC-CLIO, 2005. ISBN 978-1-57607-701-6.