There are many sports in which a round ball is used.
They include, baseball, Basketball, soccer, polo, Water Polo, volleyball, dodgeball, Field Hockey, golf, tennis and lacrosse.
Billiards: 9-ball (although, billiards may not be an actual sport)
Softball also uses a yellow ball.
some soccer balls are yellow
beach
Beach
Squash
There is a "double-yellow dot" ball currently used in the sport of squash.
The sport of bowling.
The sport of bowling.
You can use the ball as defense in the sport of dodgeball.
cricket
lacrosse
hurling
volleyball
volleyball
The sport baseball typically uses the phrase 'play ball'. The phrase 'play ball' is widely used in anything from little league baseball to major league baseball.