Lennon leaves Celtic with Rangers on the brink of ending their dream of a tenth consecutive title.
Celtic manager Neil Lennon has resigned as manager, a club statement has confirmed.
The 49-year-old returned for his second stint as the club's manager two years ago following Brendan Rodgers' departure to Leicester City, leading them to two league titles, two Scottish cups and a League Cup.
His departure comes with Celtic's Old Firm rivals Rangers on the cusp of becoming Scottish champions for the first time since 2011, having opened up an 18-point gap at the top of the league. In doing so, Steven Gerrard's men will deny Celtic the chance of a tenth consecutive league triumph.
"We have experienced a difficult season due to so many factors and, of course, it is very frustrating and disappointing that we have not been able to hit the same heights as we did previously," Lennon said in a
statement appearing on Celtic's website.
"I have worked as hard as ever to try and turn things around, but unfortunately we have not managed to get the kind of run going that we have needed.
"I have always given my best to the club and have been proud to deliver silverware to the Celtic supporters. The club will always be part of me. I will always be a Celtic supporter myself and I will always want the best for Celtic."
Celtic's principal shareholder Dermot Desmond added: "He has given so much to the club, and with his success over the last number of years - including winning a treble in his own right - he will be very difficult to replace.
"We thank Neil sincerely for all he has done for the club and we wish him every success going forward."
