Portmaster was a position in Starfleet that existed in the 23rd century. The title of portmaster was held by the commanding officer of a starbase. The portmaster was also the ultimate authority for maintenance at the starbase, and could determine which starships received repairs from the base and in what order. In this respect, the title was similar to that of yard superintendent.
Commodore Stone of Starbase 11 held this position in 2267. (TOS: "Court Martial")