For the mirror universe counterpart, please see T. Sullivan (mirror).
T. Sullivan was a Starfleet officer in the 23rd century.
Sullivan was listed as a Starfleet Command officer on the dedication plaques of the USS Shenzhou, the USS Discovery, and the USS Enterprise. (DIS: "The Vulcan Hello", dedication plaque; DIS: "Context Is for Kings", dedication plaque; DIS: "Such Sweet Sorrow")
This character was only mentioned in writing.
This officer was named after writer and co-executive producer Ted Sullivan.