The 22-year-old, who made only one senior appearance for Leeds, will be released when his contract expires next month.
Cairns has been on the fringes of United’s first team for several years but a substitute outing in a 5-0 defeat to Blackpool in 2011 - a night when he stepped in to replace the beleaguered Paul Rachubka - was his only opportunity.
Writing on Twitter, Cairns said: “My time (at) LUFC is finished from today. Would like to thank the club for giving me my first step in football.”
Cairns - a popular member of United’s academy - spent time on loan at Barrow and Stalybridge during his spell at Elland Road..
His final year at Elland Road was touched by tragedy following the death of his younger brother Blake in a car crash in South Yorkshire last November.