Conservatives: Margaret Thatcher (1975-90), Theresa May (2016-19)
Liberal Democrats: Jo Swinson (2019)
SNP: Nicola Sturgeon (2014-present)
Green Party (England & Wales): Caroline Lucas (2008-12, 2016-18), Natalie Bennett (2012-16), Siân Berry (2018-present)
Scottish Green Party: Lorna Slater (2019-present)
Plaid Cymru: Leanne Wood (2012-18)
DUP: Arlene Foster (2015-present)
SDLP: Margaret Ritchie (2010-11)
Alliance Party: Naomi Long (2016-present)
Brexit Party: Catherine Blaiklock (2019)
Labour:
UKIP elected a female leader in 2016, but she did not take up the role
Four females entered the last Labour leadership election. Two of them made the ballot. A man won (again).