Heather Southcott (15 November 1928 – 21 November 2014) was an Australian politician, representing the South Australian House of Assembly seat of Mitcham (now Waite) for the Australian Democrats. She was the first woman to lead a political party in South Australia.
Upon the parliamenary resignation of Robin Millhouse who represented the seat since its creation in 1955, Mitcham was won by Southcott and retained by the Democrats at the 1982 Mitcham by-election. While Millhouse originally represented the Liberal and Country League (the predecessor to the Liberal Party of Australia in South Australia), disagreement within the party over social policy direction and electoral reform saw him leave the party in 1973 to assist in the formation of the Liberal Movement, which became the New LM in 1976, which then became the Australian Democrats in 1977, and continued with the Democrats until his resignation from parliament in 1982. Southcott lost the seat at the 1982 state election to Stephen Baker from the moderate faction of the Liberal Party.
- "Vale Heather Southcott AM First woman to lead a political party in Australia". australian-democrats.org.au. 23 November 2014.