Two-ball, twoball, 2-ball, or 2 ball may refer to:
2 ball, the pool ball (pocket billiards) numbered "2" and colored blue 2 ball, the yellow snooker ball, worth two points, normally referred to as "the yellow" 2-ball, a two-dimensional -ball in mathematics, represented by the disk of a circle.
See also Ball two, the second non-strike thrown to a batter in baseball or softball