The 26-year-old was released by the Easter Road side at the end of last season.
Cairney started his career at Queen's Park and moved to Partick Thistle in 2008, scoring 20 goals during a four year spell at Firhill.
He switched to Hibs in 2012 under then manager Pat Fenlon and made 53 appearances in two years.
Meanwhile, full back Sean Clohessy has left Killie after the final year of his deal was cancelled by mutual consent.
The 27-year-old Englishman, who moved to Rugby Park from Southend last summer, played 26 times for Allan Johnston's side last season, scoring two goals.
Kilmarnock have signed former Hibernian midfielder Paul Cairney on a two year contract.