The Thessaly club are the only team outside of Athens and Salonika to win the Greek title - a feat they achieved in 1988.
"The team was completely demoralised when I came. We had an opportunity to try to reverse the situation but it was not possible. In some matches we played well and I believe we did not lose any matches easily," said coach Nikos Kostenoglou who took charge in early January.
Despite opening an impressive 16,000-capacity stadium in December, Larissa struggled with poor form throughout the season and made three coaching changes.
Asteras Tripolis were also relegated on Sunday after a 1-0 defeat at second-placed Panathinaikos.
‘The pure simplicity of the way Slot has managed the squad is probably the biggest thing I could say about him. It’s not broken, so let’s get on with it’: Liverpool legend full of admiration for Jurgen Klopp's successor at Anfield
‘I trained at Spurs and thought they’d give me a chance. But I received a letter thanking me but saying they didn’t think I was good enough – I was gutted’: How Tottenham missed out on signing Wales legend John Toshack
