St. Martin's Church is a Roman Catholic church in Split, Croatia. Built into a small space within the ancient Golden Gate of Diocletian's northern wall, it is one of the oldest churches in the city. St. Martin's Church is one of Split's tourist attractions and is known for its fine 11th century chancel screen. It is currently in the care of the Dominican sisters, who have a monastery next door. The church itself is open to public visits.

The Golden Gate, or "the Northern Gate", is one of the four principal Roman gates into the stari grad of Split. Built as part of Diocletian's Palace, it served as the main gate through which the Emperor entered the complex and was elaborately decorated to mark its status. Over the course of the Middle Ages, the gate was sealed off and lost its columns and statuary. It was reopened and repaired in modern times and now serves as a tourist attraction.