It is one of three islands in the Mona Passage, and part of the Isla de Mona e Islote Monito barrio, a subdivision of the municipality of Mayagüez, Puerto Rico.

It is 46.43 miles (74.72 km) from the Puerto Rican mainland, and 35.73 miles (57.50 km) from the island of Hispaniola (the coast of the Dominican Republic).

The high altitude of the island's shoreline makes it inaccessible by sea.

Monito has an area of 0.06 sq mi (0.16 km2) or 36.25 acres (14.67 ha), its highest point is 213 ft (65 m), and is barren.

The U.S. Coast Guard has rescued migrants off Monito Island.