Starbase 157 was a Federation starbase administrated by Starfleet. This starbase was located in the Beta Quadrant.
The starbase was operational by 2256 at the latest. (DIS: "Choose Your Pain")
In that year, this starbase's location was labeled on the star chart "Alpha/Beta Quadrant Overview" in the ready room aboard the USS Discovery. (DIS: "Magic to Make the Sanest Man Go Mad")
In 2257, during the first Federation-Klingon War, this starbase was occupied by the Klingons. (DIS: "The War Without, The War Within")
In 2366, this base picked up the final distress call from the freighter Lalo. The Lalo reported encountering an unknown cube-shaped vessel, which was later encountered and identified by the USS Enterprise-D as a Borg ship. (TNG: "The Best of Both Worlds")
In 2399, this starbase's location in neutral space was labeled on a Federation star chart that was in Fleet Admiral Kirsten Clancy's office at Starfleet Headquarters. (PIC: "Maps and Legends")
According to StarTrek.com, this starbase was located close to the Mempa sector.
According to the Star Trek: Destiny novel Gods of Night, Starbase 157 was destroyed by the Borg in 2381.
Taking place in 2409, the computer game Star Trek Online depicted Starbase 157 as being located near the Klingon border and hosting a large shipyard facility.