The fire, which broke out in trash that had been stored under a wooden rear porch, ripped through a three-flat building in the 1900 block of W. Diversey.
While all of the human occupants of the building survived, two dogs died in the fire.
The boy's name has not been released because he is a juvenile.
A series of at least 20 fires was reported in the area around the Diversey blaze in the past month.
Investigators continue to look into other suspicious fires, at least one of which is believed to have been set by a middle-aged man with a "homeless" appearance.
Image: Utah Domestic Violence Attorney