[2][3] Fox was educated at Harrow School and completed his National Service in the Loyals, having failed to gain a commission in the Coldstream Guards.

In The Go-Between he played the part of Lord Hugh Trimingham, for which he won a BAFTA award for Best Supporting Actor.

His acting ability also brought him to the attention of director Fred Zinnemann, who was looking for an actor who was not well known and could be believable as the assassin in the film The Day of the Jackal (1973).

In the film Gandhi (1982), Fox portrayed Brigadier-General Reginald Dyer, who was responsible for the Amritsar massacre in India.

He also appeared in The Bounty (1984) and Wild Geese II (1985), both opposite Laurence Olivier, and in The Importance of Being Earnest (2002), Nicholas Nickleby (2002), and Stage Beauty (2004).

He was seen in Four Quartets, a set of four poems by T. S. Eliot, accompanied by the keyboard music of Johann Sebastian Bach, performed by Christine Croshaw.

In 2010 Fox performed a one-man show, An Evening with Anthony Trollope, directed by Richard Digby Day.

[12] Fox was appointed an Officer of the Order of the British Empire for his services to drama in the 2003 New Year Honours.

[18][19] Fox spoke at the conference for the Referendum Party ahead of the 1997 general election and was a friend of its leader, James Goldsmith.

In 2010 Fox gave his support to a local campaign to prevent a supermarket being built close to his home in Dorset, citing the impact it would have upon small and independent businesses in the area.