Presented below are several TOS episode screenshots that provide a good overview of the appearance of the Captain's Quarters aboard the U.S.S. Enterprise NCC-1701. This set on the Desilu Studios Soundstage 9 was frequently redressed to accommodate the storyline of the episode being filmed and often served as the quarters for other officers and crew aboard ship, most notably Mr. Spock and Lt. Uhura.
In the 1st season episode "The Conscience of the King" (first airdate: Dec. 8, 1966), some wide angle views capture the overall layout of the room that features a distinct sleeping area, an office area and a dresser/grooming area. The Quarters are being searched by Kirk and Spock who are trying to locate a phaser on overload that has been hidden in the room ...
Some views of the sleeping area from different perspectives as seen in the episodes "Obsession", "Wink of an Eye", "The Conscience of the King", and "The Enemy Within" ...
The office area as seen in "The Conscience of the King", "The Tholian Web" and "This Side of Paradise" ...
The dresser ...
By the 3rd season episode "The Tholian Web" (first airdate: Nov. 15, 1968) some artwork on the wall in the sleeping area has replaced the plant seen in early episodes ...