In 1868 and 1874 Grant stood unsuccessfully for parliament at Marylebone. At the 1880 general election he was elected one of two Members of parliament for Marylebone and held the seat until 1885. Following the Redistribution of Seats Act 1885 the old constituency of Marylebone was divided into a number of single-member constituencies. At the 1885 general election Grant was the Liberal candidate at Marylebone East, but was defeated by his Conservative opponent, Lord Charles Beresford.
