Browne was elected by one vote as Tory Member of Parliament (MP) for Dorchester at a by-election on 23 April 1720. However, he was unseated on petition on 18 May 1720. He became High Steward of Dorchester in 1734 and held the position for the rest of his life. He was returned as MP for Dorchester at a by-election on 25 June 1737 and joined his brother John in Parliament. He did not stand again at the 1741 general election.
