Saint Isaac may refer to:
People Isaac, son of Abraham in the Old Testament Isaac of Dalmatia (died 383), confessor Isaac of Armenia (died ), Catholicos of Armenia Isaac (died ), of the Holy Monastic Fathers slain at Sinai and Raithu Isaac of Monteluco (died ), also known as Isaac of Spoleto Isaac the Syrian (6th or 7th century), also known as Isaac of Nineveh Isaac of Cordoba (died 851), of the Martyrs of Córdoba Isaac of Dafra Isaac Jogues (1607–1646) Isaac I of Optina (1810–1894) Isaac II of Optina (1865–1938)
Buildings, structures, and places Saint Isaac's Cathedral, in Saint Petersburg, Russia Saint Isaac's Square, in Saint Petersburg, Russia Saint Isaac's Bridge, the first bridge across Neva river in Saint Petersburg, Russia