Simon Williams (born 16 June 1946) is a British actor known for playing James Bellamy in the period drama Upstairs, Downstairs.

[2] His sister Polly, an actress, married his Don't Wait Up co-star and friend Nigel Havers.

He got his big break in 1971 when he made his first appearance as James Bellamy in the Upstairs, Downstairs episode "Board Wages".

His film career includes appearances in The Touchables (1968), The Breaking of Bumbo (1970), The Blood on Satan's Claw (1971), Three for All (1976), The Incredible Sarah (1976), Jabberwocky (1977), The Uncanny (1977), The Odd Job (1978), and the Peter Sellers films The Prisoner of Zenda (1979), and The Fiendish Plot of Dr. Fu Manchu (1980).

[5] Williams also played Captain Hastings in several BBC Radio 4 adaptations of Agatha Christie novels, starring John Moffatt as Hercule Poirot.

Williams has appeared in episodes of Bergerac, Dangerfield, dinnerladies, The Scarlet Pimpernel, Dalziel and Pascoe, Bad Girls, The Inspector Lynley Mysteries, Starhunter 2300, Cutting It, Heartbeat, Family Affairs, Doctors, The Bill, Diamond Geezer 2, Kingdom and First Among Equals.

Williams has also had recurring roles as Gerald Trigg in Law and Disorder in 1994 and Sir Charles Merrick in Holby City from 2000 to 2003.

In 2008, he appeared in an episode of the BBC spy series Spooks as bank owner Sir Francis Denham.

In 2010, Williams contributed to the CD We Will Remember Them, published by the Royal British Legion, where he read three of the poems.

He has donated his time and expertise to the Sir Terence Rattigan Charitable Trust, the King George V Fund for Actors and Actresses, and several other charities.