O
- Ed Oates - co-creator of Oracle database, co-founder of Oracle Corporation
- Martin Odersky - Scala
- Jarkko Oikarinen - creator of Internet Relay Chat (IRC)
- Andrew and Philip Oliver, The Oliver Twins - Many Sinclair ZX Spectrum games including Dizzy
- John Ousterhout - creator of Tcl/Tk
- Onel de Guzman - A Filipino Programmer who created the ILOVEYOU virus on May 4, 2000.
Read more about this topic: List Of Programmers