Olin may refer to:

People

Organizations

• OLIN, American landscape architecture firm
• Olin Business School at Washington University in St. Louis
• Olin College, an undergraduate engineering college in Massachusetts
• Olin Corporation, a chemical corporation with a history of producing chemicals and ammunition
• Olin Edirne, the former name of Turkish basketball team Eskişehir Basket
• F. W. Olin Foundation, a foundation endowed by Franklin W. Olin
• John M. Olin Foundation, a foundation endowed by John M. Olin
• Preston and Olin Institute, a defunct Methodist boys' school now a part of Virginia Tech

Places

• Olin, Iowa, a small city in the United States
• Olin, North Carolina, an unincorporated community in the United States
• Olin, Poland
• Olin's Covered Bridge, the only bridge in Ashtabula county, Ohio named for a family
• Olin Observatory, an astronomical observatory in New London, Connecticut
• Olin Sang Ruby Union Institute, a Jewish overnight summer camp in Wisconsin

Fictional characters

• Olin, a character on the TV series General Hospital
• Gerald Olin, character in the 2007 film 1408 portrayed by Samuel L. Jackson

Other uses

• Nahui Ollin, also spelled Ōlīn, a concept in Aztec mythology potentially related to Tōnatiuh
• Olin (spider), a spider genus in the family Trochanteriidae
• Olin Palladium Award, an award given by the Electrochemical Society
• Olin Raschig process, an industrial process for manufacturing hydrazine