Oh

Oh is a 24th century female Romulan operative of the Zhat Vash who posed as a Vulcan and served in the Federation Starfleet as a commodore in the late 24th century.

In 2399, Oh directed a covert operation involving Narissa Rizzo and Narek, aimed at obtaining information about the whereabouts of androids similar to Dahj and Soji Asha. According to Rizzo, she had profound reservations. (PIC: "Maps and Legends")

''Oh was portrayed by Tamlyn Tomita. She is the first commodore to be seen in the 24th century. Although the episode itself does not give any explicit indication that Oh is a Romulan and not a Vulcan, her make-up was established as Romulan in The Ready Room: "Episode 15".