A Soccer Ball, or Football (in countries outside of US), is a spherical ball used in the sport Soccer or Football. It is used in every video game that is based around the sport, and various other titles as well.
Super Smash Bros. series
Starting with Super Smash Bros. Brawl, the soccer ball appeared as a weapon that could be kicked by the character. After being kicked, it may or may not hit one of your opponents, thus delivering damage. According to the trophy, the ball is from Soccer and Super Mario Strikers.