'Harrow' comes from Old English hearg, a heathen temple or shrine.
The temple was probably on the hill of Harrow, where St Mary's Church now stands. South Harrow grew out of the old hamlet of Roxeth, first recorded in 845, whose name may mean rooks' heath or rooks' place, or recall a man called Hrōc. The station opened in 1903 as South Harrow for Roxeth and Northolt.