Proudfoot was born in Crook, County Durham where his father was manager of the local Broughs grocery shop. Broughs was a family-owned grocery chain serving Northern England. It was a British pioneer of the self-service model whereby customers took goods from open shelves and paid for them at a check-out desk rather than being served at a counter. Proudfoot (senior) held a temporary commission and had won the Military Cross while serving in the British army during the First World War. The older Proudfoot had political ambitions but these were restrained by Broughs who refused to allow him to stand as a Conservative candidate in local council elections.