The 43-year-old conservative mayor was given two weeks to vacate his office to allow for "administrative changes" in running Canada's largest city, the Toronto Sun reported.
Ford's role in coaching high school football and his charity for raising funds for football programs was at the root of the case.
In 2010, the court heard Ford used his staff and city letterhead to send out appeals for donations to the charity, which is a breach of the Municipal Conflict of Interest Act.
Ford didn't deny the allegations and said he had never read the act or a city handbook of ethics and conduct for elected officials.
In February, the city integrity commissioner had called for council to vote on whether Ford should personally repay some $3,000 raised. The council and Ford voted to reject the recommendation, but a private citizen went to court complaining Ford should have abstained from the vote.
Judge Charles Hackland ruled Monday Ford had crossed a line.
"His actions were not done by reason of inadvertence or a good faith error of judgment," Hackland said.
The judge could have banned Ford from running for office for seven years.
Ford is expected to appeal to a three-judge Ontario court and would remain in office until their ruling.