One-wall handball, also known as 1-wall, wallball or international fronton, is an indirect style of a ball game where the player hits a small rubber ball with their hand against a wall. The goal of the game is to score more points than the opponent. The player then hits the ball, and the ball bounces off the wall and the floor within court lines, if the opponent fails to return the ball, the player scores a point. The sport was created to bring together varieties, such as American handball, Basque pelota, Patball, Gaelic handball, Pêl-Law and Valencian frontó.

American handball, known as handball in the United States and sometimes referred to as wallball, is a sport in which players use their hands to hit a small, rubber ball against a wall such that their opponent(s) cannot do the same without the ball touching the ground twice or hitting out-of-bounds. The three versions are four-wall, three-wall and one-wall. Each version can be played either by two players (singles), three players (cutthroat) or four players (doubles), but in official tournaments, singles and doubles are the only versions played.