It's all down to the final performances as the two singers left in the competition take the stage in Part 1 of this two-part season finale. Former winner Phillip Phillips also performs, as does pop songstress Carly Rae Jepsen. Fox/CTV, 7 p.m.
CSI: Crime Scene Investigation
A journalist shadows the team as they investigate a series of murders that appear to mimic the sins in Dante's Inferno. This season finale includes a special appearance by Black Sabbath, who debut their new song End of the Beginning. CBS/CTV, 9 p.m.
With Dark Archer poised to unleash his vengeance on The Glades, Oliver and Diggle set out to stop him in this season finale. Elsewhere, Thea steps into the line of fire of Malcolm's dastardly plan as she races to find Roy. CTV, 10 p.m.
George Stroumboulopoulos: Bruce Greenwood
Jay Leno: Usher, Nick Offerman
David Letterman: Ed Helms, Hoda Kotb
Jimmy Kimmel: J.J. Abrams, Huey Lewis & the News
Craig Ferguson: Ice-T, Paula Poundstone
Jimmy Fallon: Julie Bowen, Demi Lovato
The Daily Show: Olympia Snowe
Conan O'Brien: Zach Galilfianakis, Jim Gaffigan