"Many fans legitimately hate him because while wrestling has made him a billionaire, many wrestlers say he's treated them terribly."
The expletive-filled rant, which reportedly saw WWE shares dip nearly three per cent on Monday, was strongly condemned in a statement from McMahon's company.
Oliver's main gripe was with McMahon's company hiring wrestlers as independent contractors rather than making them employees.
"An independent contractor is someone you might hire for a specific, limited task. Like a plumber or an accountant, wrestlers aren't either of those things," Oliver said.
"As independent contractors, wrestlers are exempt from most discrimination and occupational safety laws. They don't get paid annual leave, pensions or health insurance."
Oliver showed a graph based on data from FiveThirtyEight which showed premature wrestler death rates far outpaced the general public and former NFL players.
"(When) independent contractors (are) working in a monopolised industry largely free from meaningful oversight who are able to be fired at any time, you wind up with an environment with huge potential for unsafe conduct," he said.
"Even the NFL, for all its massive faults, now offers players health reimbursement accounts and have established a legacy fund for older players who may be dealing with health issues," Oliver said. "And when you have lost the moral high ground to the f***ing NFL, you are morally subterranean."
Oliver called on fans to protest the current state of affairs at WrestleMania 35, saying it was the only way of forcing change.
"There's one group that even McMahon occasionally seems to listen to, and that's the fans," Oliver said.
"The event is live, the crowd is miked, they won't be able to cut the chants out. I'm not saying the fans should do that, or make signs, or make lots of signs, I'm just saying I really hope they make their voices heard on this."
The WWE hit back in a statement, accusing Oliver of "ignoring the facts" and inviting him to WrestleMania.
"John Oliver is clearly a clever and humorous entertainer, however the subject matter covered in his WWE segment is no laughing matter," the statement read.
"Prior to airing, WWE responded to his producers refuting every point in his one-sided presentation. John Oliver simply ignored the facts.
"The health and wellness of our performers is the single most important aspect of our business, and we have a comprehensive, longstanding Talent Wellness program.
"We invite John Oliver to attend WrestleMania this Sunday to learn more about our company."