The Men's 90 kg Judo competition at the 2008 Summer Olympics was held on August 13 at the Beijing Science and Technology University Gymnasium.

This event was the third-heaviest of the men's judo weight classes, limiting competitors to a maximum of 90 kilograms of body mass.

The tournament bracket consisted of a single-elimination contest culminating in a gold medal match.

The two judokas who lost in the semifinals faced the winner of the opposite half of the bracket's repechage in bronze medal bouts.

The gold and silver medalists were determined by the final match of the main single-elimination bracket.