Andrew Sharp Peacock AC GCL (born 13 February 1939) is a former Australian politician and diplomat.
He served twice as leader of the Liberal Party (1983–1985 and 1989–1990), leading the party to defeat at the 1984 and 1990 elections.
He had earlier been a long-serving cabinet minister.
Peacock was born in Melbourne, and attended Scotch College before going on to study law at the University of Melbourne.
A former president of the Young Liberals, he was elected to Parliament at the age of 27, filling the blue-ribbon seat of Kooyong, vacated by Sir Robert Menzies.
Peacock was appointed to cabinet in 1969 by John Gorton, and later served under William McMahon and Malcolm Fraser.
He held a variety of portfolios, most notably serving as Minister for Foreign Affairs from 1975 to 1980.
He unsuccessfully challenged Fraser for the Liberal leadership in 1982, but was then elected as Fraser's successor following the party's defeat at the 1983 election.
At the 1984 election, the Peacock-led Coalition slightly reduced Labor's majority.
He resigned the Liberal leadership the following year after failing to have his deputy John Howard removed; he was duly replaced by Howard.
He remained a member of the shadow cabinet, and in 1987 unsuccessfully challenged Howard for the leadership; he was instead elected deputy leader.
Peacock finally returned as leader in 1989.
However, his second term lasted less than a year, as he resigned after another electoral defeat in 1990.
Peacock left politics in 1994, and was later appointed Ambassador to the United States (1997–1999).