Humphreys said: "I am honoured to have been elected by my fellow members of the management committee and look forward to taking up the position of PFA chairman at the AGM in November. I am fully committed to the role that the PFA plays across all areas of football and will make every effort to continue the great work which Clarke has put in during his time as chairman."
Humphreys first made an impact at Sheffield Wednesday in the Premier League before moving to Hartlepool in 2001 and beginning 12 years at the club in which he made 548 appearances.
Carlisle will be a big act to follow having been at the forefront of recent cases involving racial abuse in football and recently presenting a highly regarded TV programme on depression in football. Carlisle is expected to continue in his media and campaigning activities.