Shane Alexander, 2nd Earl Alexander of Tunis

Shane William Desmond Alexander, 2nd Earl Alexander of Tunis (born 30 June 1935), known as Lord Rideau from 1952 to 1969, is a British peer.

Alexander is the eldest son of Field Marshal Harold Alexander, 1st Earl Alexander of Tunis and Lady Margaret Bingham (1905–1977), the daughter of the 5th Earl of Lucan. He was educated at Harrow and Ashbury College. He joined the Irish Guards in 1954. He succeeded his father in the earldom following his death on 16 June 1969.

Alexander served as Lord in Waiting from 8 January 1974 until 4 March 1974 at the end of Edward Heath's premiership. He has also been a director of the Pathfinder Financial Corporation in Toronto in 1980.

As a descendant of the Earls of Caledon he is also in the remainder to that title and was the heir presumptive from 1980 to 1990. The heir presumptive to the Earl Alexander of Tunis title is his brother the Hon. Brian James Alexander, CMG (born 1939) who has no children, and so is the only person in remainder to the Earldom.

He was married twice: firstly to Hilary van Geest on 14 July 1971 until the marriage was dissolved in 1976.

He married secondly The Hon. Davinia Mary Woodhouse, daughter of James Woodhouse, 4th Baron Terrington, on 22 July 1981. She is a former Lady in Waiting to Princess Margaret.

They have two daughters together:

• Lady Rose Margaret Alexander (born 1982), a god-daughter of Princess Margaret.
• Lady Lucy Caroline Alexander (born 1984), married James Agar, Viscount Somerton, son of the 6th Earl of Normanton in June 2012

Earl Alexander of Tunis lives in London.