Masaka was founded as a township in 1953. It became a town council in 1958 and a municipality in 1968. Masaka was a strategically important location during the Uganda–Tanzania War (1978–79), and was accordingly garrisoned by Uganda Army troops.

Masaka is approximately 132 kilometres (82 mi) to the south-west of Kampala on the highway to Mbarara. The city is close to the Equator. The coordinates of Masaka are 0°20'28.0"S, 31°44'10.0"E (Latitude:-0.341111; Longitude:31.736111). Masaka lies at an average elevation of 1,288 metres (4,226 ft) above sea level.