Lowestoft was a parliamentary constituency centred on the town of Lowestoft in Suffolk. It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected by the first past the post voting system.

Lowestoft is a coastal town and civil parish in the East Suffolk district of Suffolk, England. As the most easterly UK settlement, it is 110 miles (177 km) north-east of London, 38 miles (61 km) north-east of Ipswich and 22 miles (35 km) south-east of Norwich, and the main town in its district. The estimated population in the built-up area exceeds 70,000. Its development grew with the fishing industry and as a seaside resort with wide sandy beaches. As fishing declined, oil and gas exploitation in the North Sea in the 1960s took over. While these too have declined, Lowestoft is becoming a regional centre of the renewable energy industry.