An officers' club was an establishment found in Starfleet installations or starships for officers to relax and unwind.
In the 2260s, Starbase Vanguard had an officers' club which was situated in the station's core and overlooked hangar bay three.
However, it was unpopular with some officers, many preferring to go to Manón's instead. Captain Rana Desai thought of the officers' club as "a drab gray box with chairs". (VAN novel: Precipice)
The Luna-class USS Titan had an officers' club in the 2380s.
In 2386, Melora Pazlar noted that she'd been stood up several times by Xin Ra-Havreii at the ship's officers' club. (TTN novel: Sight Unseen)