A clay court is one of the types of tennis court on which the sport of tennis, originally known as "lawn tennis", is played. Clay courts are made of crushed stone, brick, shale, or other unbound mineral aggregate depending on the tournament.

The French Open uses clay courts, the only Grand Slam tournament to do so. Clay courts are more common in Continental Europe and Latin America than in North America, Asia-Pacific or Britain. Two main types exist: red clay, the more common variety, and green clay, also known as "rubico", which is a harder surface. Although less expensive to construct than other types of tennis courts, the maintenance costs of clay are high as the surface must be rolled to preserve flatness.