The men's downhill in the 2021 FIS Alpine Skiing World Cup consisted of seven events. The original schedule had contained nine downhills, but a rescheduled one on 5 March in Saalbach-Hinterglemm, Austria, was canceled due to fog and continual snowfall after just nine skiers had finished, and the downhill during World Cup finals week was also canceled.

Matthias Mayer is an Austrian retired World Cup alpine ski racer and Olympic champion.