William Stephen Ian Whitelaw, 1st Viscount Whitelaw of Penrith (June 28, 1918 - July 1, 1999) was a British Conservative politician.

He was the first British Secretary of State for Northern Ireland after the imposition of direct rule in March 1972 and he served in that capacity until November 1973. During his time in Northern Ireland he introduced 'special category' status for paramilitary prisoners.

In the later Thatcher government he was Deputy Prime Minister and Home Secretary from 1979 to 1983, and Deputy Prime Minister and Leader of the House of Lords from 1983 to 1988.

He was a Conservative MP from 1955 until he went to the House of Lords in 1983.

{| border="2" align="center" |- |width="30%" align="center"|Preceded by:
New Creation |width="40%" align="center"|Viscount Whitelaw |width="30%" align="center"|Followed by:
Extinct |}