Role played by Nolan Gould.

Luke Dunphy is Claire and Phil's rambunctious son, who is often doing his own thing. At times he can be a trouble maker, once shooting his sister with a toy gun and getting into a fight with Manny at school. Luke is very innocent and does not always understand the repercussions of his actions, like most children; he once announced at a family gathering that his mom thought her dad's new wife was a "coal digger." He is also thought to be a bit vacuous, because of many questionable actions; some of these actions that he is known for are getting his head stuck in the banister and jumping on the trampoline wearing only underwear and a box on his head.