The 1921 UCI Road World Championships (the annual world championships for bicycle road racing organized by the Union Cycliste Internationale) took place in Copenhagen, Denmark on Thursday 4 August 1921.

It was the first official World Championships organized by the UCI.

The championships were only for amateur men.

[1] From 30 July to 8 August, the 1921 UCI Track Cycling World Championships were organized on the velodrome of Ordrup, near Copenhagen.

Sweden won the nations classification (total time of the first four riders per nation) ahead of France and Denmark.