Northampton was born at Castle Ashby, Northamptonshire, the second son of Admiral William Compton, 4th Marquess of Northampton, and his wife Eliza (née Elliot). He was educated at Eton College and Trinity College, Cambridge, where he graduated as B.A..
He received the courtesy title of Earl Compton in 1887 on the death of his elder brother.
He served in the Diplomatic Service as Second Secretary to the British embassies in Paris, Rome and St Petersburg. He then served as Private Secretary to the Lord Lieutenant of Ireland, the Earl Cowper, between 1880 and 1882, and was elected to the House of Commons for Stratford-on-Avon in December 1885. He held this seat until July the following year and then sat for Barnsley from 1889 to 1897. In the latter year Northampton succeeded his father in the marquessate and entered the House of Lords.
Northampton, who was a major landowner in Clerkenwell and north London, was elected a founder member of London County Council for Finsbury in 1889, then served as County Alderman from 1892 to 1895. He was J.P. for the counties of Warwickshire and Northamptonshire.
From 1908 he was Honorary Colonel of the London Heavy Brigade of the Royal Garrison Artillery.