What actors and actresses appeared in The Muppets All-Star Comedy Gala - 2012?

The Muppets All-Star Comedy Gala - 2012 featured a star-studded lineup, including:

Musicians:

* Justin Timberlake

* Selena Gomez

* Lady Gaga

* Neil Patrick Harris

* Ricky Gervais

* Josh Groban

* Reese Witherspoon

* Will Ferrell

Comedians:

* Jason Segel

* Amy Poehler

* Bill Hader

* Kristen Wiig

* Jack Black

Other notable appearances:

* Steve Martin

* Elton John

* Tom Hanks

* Zach Galifianakis

* Jim Parsons

This list is not exhaustive, and there were many other cameo appearances throughout the special.