Gatchina is a town and the administrative center of Gatchinsky District in Leningrad Oblast, Russia. It lies 45 kilometers south-south-west of St. Petersburg, along the E95 highway which links Saint Petersburg and Pskov. Population: 92,937 ; 88,420 ; 79,714 .It was previously known as Khotchino, Gatchina, Trotsk, and Krasnogvardeysk.