 Fitzmaurice was educated at Eton and Trinity College, Cambridge, where he was President of the Cambridge Union in 1866.He was called to the Bar at Lincoln's Inn in 1871, but never practised.In 1868 Fitzmaurice was elected unopposed to Parliament for the family constituency of Calne, a seat he would hold until 1885, and served as Parliamentary Private Secretary to Robert Lowe, Chancellor of the Exchequer and later Home Secretary, from 1872 to 1874, when the Liberals fell from office.