Born Freeman Thomas, he was educated at Eton and Trinity College, Cambridge. He assumed the surname "Freeman-Thomas" by Royal Licence in 1892, and was Member of Parliament for Hastings and for Bodmin from 1900 to 1910.
He was raised to the peerage as Baron Willingdon, of Ratton in the County of Sussex, in 1910, and was further created Viscount Willingdon, with the same territorial designation, in 1924, Earl of Willingdon and Viscount Ratendone, of Willingdon in the County of Sussex, in 1931, and finally Marquess of Willingdon in 1936. This was the most recent Marquessate created in the Peerage of the United Kingdom.
He donated the Willingdon Cup to the Royal Canadian Golf Association in 1927, for Canadian interprovincial amateur golf competition. The cup has been contested annually since that year.
The Willingdon Club in Bombay was established with membership open to both Indians and British after he was denied entry, although he was Viceroy, with Indian friends to the Royal Bombay Yacht Club. The Willingdon Club continues to flourish today.
Lord Willingdon was the Chief Scout for India, in which he served with real and sincere interest, not simply in an ex officio position. He was convinced that Scouting was contributing to the welfare and development of India, particularly in the villages. At his request, J. S. Wilson paid special attention to the cooperation of Scouting with village development.
He died in 1941, and was succeeded by his younger son Inigo, Viscount Ratendone, his elder son, Lieutenant the Hon. Gerard Freeman-Thomas, having been killed in the First World War whilst serving with the Coldstream Guards. He and his wife are buried in the nave of Westminster Abbey.