St. Augustine Amphitheatre, Open-air theatre in Anastasia State Park, St. Augustine, United States.

St. Augustine Amphitheatre is an open-air theatre located within Anastasia State Park, featuring seating arranged in a semicircular design that faces toward a large performance stage. The venue was built to accommodate large crowds for various types of events and performances.

The amphitheatre was built in 1965 to mark the 400th anniversary of St. Augustine's founding, originally with 2,000 seats, on land that had been part of Anastasia State Park. It was constructed inside one of the old coquina quarries that supplied building stone for the city and the Castillo de San Marcos. Paul Green's Cross and Sword, the official state play from 1973, ran until 1996; after a $8.7 million renovation, the venue reopened in August 2007.

The site's name comes from the Spanish colonial settlement it commemorates, and its grounds occupy one of the old coquina quarries that supplied stone for St. Augustine and the Castillo de San Marcos. Since 2023 the venue has been run by SJC Cultural Events, Inc. A Saturday farmers' market brings produce, seafood, cheeses, baked goods and work by local artists, with live entertainment many weeks.

The venue sits within a state park and is accessible by car with parking available on the grounds. Booking seats in advance is recommended since availability varies depending on the event and expected attendance.

The amphitheatre was built inside one of the old coquina quarries that supplied building stone for St. Augustine and the Castillo de San Marcos. Its first production was Paul Green's Cross and Sword, a symphonic drama of the Spanish settlement that became Florida's official state play in 1973 and ran until 1996.