The boxing judge who Jake Paul said helped fix two recent, huge fights is now firing back at the former YouTube star ... suing the 25-year-old for defamation.
Glenn Feldman filed the suit in New York on Monday, TMZ Sports has learned ... claiming Paul "made outrageously false and baseless accusations" against him during an interview last month.
Paul made the comments -- which also implicated famed boxing promoter Eddie Hearn, who has already sued Paul -- during a talk with IFL TV on Sept.