Kathleen Joan "Kate" Costain (née Beecroft) is a Manx politician who is a former Leader of the Liberal Vannin Party and was a Member of the House of Keys for Douglas South from 2011 to 2020.
She stood unsuccessfully for the Liberal Vannin Party in Middle in the 2006 Manx general election but later became a Braddan Commissioner from 2007 to 2011.
[2] She stood unsuccessfully again in Douglas East in a by-election in 2010, coming second and only seven votes behind Chris Robertshaw who won.
In February 2014, Peter Karran, the Leader of the Liberal Vannin Party, renounced his leadership in favour of Beecroft.
"[4] She once revealed aspirations to bring more women into the House of Keys and to field a Liberal Vannin candidate in every constituency in the 2016 Manx general election.