Danny DeVito Frank Reynolds Actor Charlie Day Charlie Kelly Actor, Executive Producer Glenn Howerton Dennis Reynolds Actor, Executive Producer Kaitlin Olson Deandra "Sweet Dee" Reynolds Actor Rob McElhenney Mac Actor, Executive Producer Mary Elizabeth Ellis Waitress Guest Star Jessica Collins Jackie Denardo Guest Star Josh Groban Himself Guest Star T.J. Hoban Rex Guest Star David Hornsby Executive Producer Tom Lofaro Executive Producer Michael Rotenberg Executive Producer Megan Ganz Executive Producer Nick Frenkel Executive Producer Rob Rosell Executive Producer Scott Marder Executive Producer Victor Hsu Executive Producer