The 1921 International Lawn Tennis Challenge was the 16th edition of what is now known as the Davis Cup. In the playoff finals, newcomers Japan surprised Australasia 4–1, but would fall to defending champions the United States in the Challenge Round. The final was played 2–5 September at the West Side Tennis Club in New York City.

Teams

The tournament saw a boom in entries, with a record 12 teams entering to challenge for the cup. Argentina, Czechoslovakia, Denmark, India, Japan, the Philippines, and Spain all entered the tournament for the first time, although Argentina and the Philippines withdrew after the draw.

Draw

First round

Czechoslovakia vs. Belgium Great Britain v Spain Canada vs. Australasia

Quarterfinals

France vs. India Australasia vs. Great Britain

Semifinals

India vs. Japan Australasia vs. Denmark

Final

Japan vs. Australasia

Challenge Round

United States vs. Japan