OLC, a three-letter acronym (TLA) that may refer to:
- Oak leaf cluster, a subsequent award of a military decoration
- Office of Legal Counsel in the U.S. Federal Government
- Online Contest, a glider, hang glider, and paraglider soaring competition
- Online creation, a software feature in MUDs that allows editing the world while interacting with it
- open-loop control, a concept in control theory
- The Oriental Land Company
- Online Communication, in Manga
- OLC Barcelona Sheet Music, an online publisher of free and low cost sheet music