San Pedro is a town on the southern part of the island of Ambergris Caye in the Belize District of the nation of Belize, in Central America. Accor…San Pedro is a town on the southern part of the island of Ambergris Caye in the Belize District of the nation of Belize, in Central America. According to the 2015 mid-year estimates, the town has a population of about 16,444. It is the second-largest town in the Belize District and largest in the Belize Rural South constituency. The once sleepy fishing village was granted the status of a town in 1984.