Robert Adam Ross Maclennan, Baron Maclennan of Rogart, PC (26 June 1936 – c. 18 January 2020), was a British Liberal Democrat politician, formerly a life peer.

He was the last leader of the Social Democratic Party (SDP), serving during the negotiations that led to its merger with the Liberal Party in 1988. He then became joint interim leader of the new party, known as the Social and Liberal Democrats (SLD) before later becoming the Liberal Democrats. He served as a Member of Parliament (MP) from 1966 to 2001, when he was elevated to the House of Lords.

Early life

MacLennan's father, Sir Hector MacLennan, was a renowned gynaecologist and obstetrician. His mother, Isobel Adam, was also a doctor and public health activist. He was educated at Glasgow Academy; Balliol College, Oxford; Trinity College, Cambridge; and Columbia University, New York City. He is the brother to David MacLennan, Elizabeth MacLennan, and Kenneth MacLennan.

In Parliament

He became Member of Parliament (MP) for the constituency of Caithness and Sutherland in 1966, and serving until 1997; and for Caithness, Sutherland and Easter Ross after boundary changes, from 1997 to 2001.

He was first elected as a member of the Labour Party and served as a junior minister in the Labour government of 1974–1979, but in 1981 defected to become a founder member of the SDP. He was one of the few SDP MPs to keep their seats in the 1983 general election. After his stint as SDP Leader in 1988, he served as a front bench spokesman for the Liberal Democrats, and as their president from 1994 until 1998.

He was appointed to the Privy Council in 1997.

After his retirement at the 2001 general election, he was raised to the House of Lords, elevated to a life peer as Baron Maclennan of Rogart, of Rogart in Sutherland. He was the party's Cabinet Office and Scotland spokesman in the House of Lords until 2015.

Death

On 18 January 2020, it was reported that Maclennan had died at the age of 83.