Kazachye Cemetery (Russian: Казачье кладбище), formerly known as Communist Square (Russian: Коммунисти́ческая площа́дка) and also known as the Internal Cemetery of the Alexander Nevsky Lavra (Russian: Вну́треннее кла́дбище Алекса́ндро-Не́вской ла́вры) is a historic cemetery in the centre of Saint Petersburg. It is part of the Alexander Nevsky Lavra, and is one of four cemeteries in the complex.
Established during the Russian Revolution in 1917 as a burial ground for Cossacks killed during the July Days, it was soon used for the interment of several prominent communist activists, and was the site of mass graves of those who had died to defend communism in the Russian Civil War. In light of this, it became known as "Communist Square". The graves of several high profile military leaders and scientists were located here during the 1920s and 1930s, with further burials taking place during the siege of Leningrad. More interments took place in the postwar years, but the number eventually declined during the last years of the twentieth century, until the cemetery was closed. An estimated 700 people were buried here during the years of its operation, and in 2009 its original name, "Kazachye", was restored.