Mossel Bay (Afrikaans Mosselbaai) is a harbour town of about 130,000 people on the Southern Cape (or Garden Route) of South Africa. It is an important tourism and farming region of the Western Cape Province. Mossel Bay lies 400 kilometres east of the country's seat of parliament, Cape Town (which is also the capital city of the Western Cape Province), and 400 km west of Port Elizabeth, the largest city in the Eastern Cape Province. The older parts of the town occupy the north-facing side of the Cape St Blaize Peninsula, whilst the newer suburbs straddle the Peninsula and have spread eastwards along the sandy shore of the Bay.
The town's economy relied heavily on farming, fishing and its commercial harbour (the smallest in the Transnet Port Authority's stable of South African commercial harbours), until the 1969 discovery of natural offshore gas fields led to the development of the gas-to-liquids refinery operated by PetroSA. Tourism is another driver of Mossel Bay's economy.