Captain Richard McKenzie was a Starfleet officer in the 24th century.
In 2365, he was listed as the commander of the USS Yamato on a Starship Deploy Status chart in the Starbase 173 courtroom. (TNG: "The Measure Of A Man", okudagram)
In 2368, he was listed as an Engineering Group officer on the second version of the dedication plaque of the USS Enterprise-D. (TNG: "Silicon Avatar", dedication plaque)
This character was only mentioned in writing.