The Constituency of Estuary was a constituency of the House of Representatives of Howland. The constituency was created in 1949 and was one of the original 30 constituencies contested at the first election. It was named for the estuary of the River Barrow, a largely agricultural region. During its existence, it was based around the towns of Milburn, Lorelai and St. Peters. The constituency was marginally to fairly safe for the Independence Party, and was held by that party during its entire existence. During the reapportionment of 1955, the constituency was abolished and the area was incorporated into neighboring constituencies, as well as the new Constituency of Parker.