The shooting happened around 6:40 p.m. in the 1400 block of West 3rd Street.
According to investigators, an 18-year-old man had gotten into a shootout with several other people.
That 18-year-old was also shot. Both he and the 4-year-old are in stable condition.
Police say the teen was found to be wanted on an unrelated matter, and charges against him for the shooting are pending.
Action News has learned the shooting happened in the area of a child's birthday party.
The circumstances of this incident remain under investigation.