Starbase 515 was a Federation Starfleet starbase active in the 24th and 25th centuries. The starbase was known for its advanced biomedical facilities.
In 2358, Richard James reported for duty aboard the USS Repulse at Starbase 515. (Star Trek: The Quarterdeck Breed)
USS Enterprise-D personnel Captain Jean-Luc Picard and acting Ensign Wesley Crusher arrived at Starbase 515 in 2365, Picard for a cardiac replacement and Crusher to sit his Starfleet Academy entrance examinations. (TNG: "Samaritan Snare")
Dr. Thomas Alden was stationed at Starbase 515 before he accepted Bryce Avari's offer to be chief medical officer on the USS Phoenix in 2422. (Star Trek: Phoenix)