The Men's K1 at the 2021 ICF Canoe Slalom World Championships took place on 23 and 25 September 2021 at the Čunovo Water Sports Centre in Bratislava.

Italian underdog Marcello Beda won silver in his first international final, while Joan Crespo matched his result from 2019 with bronze.

Athletes start in the reverse order of their heats position in the semifinal and complete a single run, with the top 10 advancing to the final.

With both Germans Noah Hegge and Stefan Hengst setting equal times of 85.95 in the first heats run to finish 30th, 41 athletes progressed to the semifinal.

The semifinal was won by home favourite Jakub Grigar, with a time of 85.16, ahead of Hegge and Marcello Beda, both making their first World Championship final.

By finishing 9th in the semifinal, Brazilian Pedro Gonçalves became the first South American to progress to the World Championships final in this event since Thomas Bersinger placed 4th in 2014.