Jabarkan O dari Daftar karakter Star Trek

Keiko O'Brien, istri Miles O'Brien

Miles O'Brien, transporter chief on the Enterprise-D, Chief of Operations at DS9

Molly O'Brien, putri Miles dan Keiko O'Brien

Katie O'Claire Alias used by Kathryn Janeway while in Fair Haven

Odala (VOY, "Distant Origin") Saurian minister who refuses to believe Professor Gegen's distant origin theory of their race.

Odan (TNG, "The Host"), a precedent for Trills disregarded on DS9

Odo (DS9) changling security officer

Ralph Offenhouse 20th Century human cryogenically frozen and discovered by the Enterprise-D

Alyssa Ogawa, nurse aboard the Enterprise-D

Thadiun Okona (TNG, "The Outrageous Okona") Captain of a small freighter

Omet'iklan (DS9, "To The Death") Jem'haddar First who threatened to kill Sisko after completing a mission to kill renegade Jem'haddar soldiers.

Onaya (DS9, "The Muse") Vampiric being who feeds on creative energy. She claims to have helped artists all over the quadrant, including Earth's William Butler Yeats.