The Turkish hitman joined in the 2015 summer transfer window from Dundee United but failed to make a significant impact at Parkhead.
He played semi-regularly during the first half of his debut campaign before spending the second part of the season on loan at Eskisehirspor.
He featured only four times under Brendan Rodgers before moving out on loan again in January 2017, signing for Polish side Pogon Szczecin.
Last season he failed to make an appearance for the Scottish champions, spending the term on loan at Plymouth and then Motherwell.
Stephen Robinson previously stated his intent to keep Ciftci at Fir Park on a longer deal, though with 12 months remaining on the player’s contract at Parkhead the Motherwell boss admitted it would be difficult.
Their interest may be rekindled after today’s news with Celtic announcing that Ciftci will be leaving the club a year ahead of schedule.
A short statement read: “Celtic Football Club can confirm that Nadir Ciftci will be leaving the club on June 30, 2018. Currently on loan to Motherwell, everyone at Celtic wishes Nadir all the very best for the future.”