Santa Catalina,an island in the Santa Barbara group off the coast of southern California. It is part of Los Angeles County, though separated from the mainland by some 20 miles (32 km) of the San Pedro Channel. Santa Catalina is 22 miles (35 km) long and as much as 8 miles (13 km) wide. The island is hilly and wooded and has resort facilities, concentrated around Avalon, the only city. Attractions include beaches, a boardwalk, a historical museum, and marine gardens that can be viewed through glass-bottomed boats. Deep-sea fishing is a popular sport.

Santa Catalina had been inhabited by Indians for thousands of years before it was reached by the Portuguese navigator Juan Rodríguez Cabrillo in 1542. It was given its present name by Sebastían Vizcaíno in 1602. Santa Catalina was largely undeveloped until 1919, when William Wrigley, Jr., bought it and established resort facilities.