- Charlie Day (Charlie Kelly)
- Glenn Howerton (Dennis Reynolds)
- Rob Mac (Ronald 'Mac' McDonald)
- Kaitlin Olson (Dee Reynolds)
- Danny DeVito (Frank Reynolds)
It's Always Sunny in Philadelphia — S0E63
Episode: It's Always Sunny in Philadelphia Christmas Singalong
Air Date: 2010-12-10
Runtime: 22 min
Overview
It's Always Sunny in Philadelphia Christmas Singalong from the "A Very Sunny Christmas" home release