The 2-year-old boy was treated by paramedics after being shot in the ear by one pellet.
The man who was wounded was reportedly standing outside an apartment complex when he was struck in the chest by multiple shotgun pellets.
Witnesses said they saw two vehicles leaving the scene - a white, late-model van and a blue Ford Explorer.
The injuries suffered by the little boy and the adult are not life-threatening.
If you have any information about this case, you're urged to call L.A. County Sheriff's Department in Compton at (310) 605-6500.