Tulsa Race Massacre — racially charged mass attack in Tulsa, Oklahoma, USA in May-June 1921

1921 battle of the Third Silesian Uprising

Centennial event in Peru

1921 battle of the Turkish War of Independence

1921 treaty which recognised that a land-locked state could register ships and sail them on the sea using its own flag

1921 South American Championship — 1921 edition of the association fotoball South American Championship

1921 treaty between Soviet Russia and Turkey

Kronstadt rebellion — uprising against the Bolsheviks in March 1921

World Chess Championship 1921

Conflict between Panama and Costa Rica in 1921

1921 short naval battle of the Russian Civil War