(All times Eastern.)
The Big Bang Theory (CBS at 8) Sheldon and Amy turn to math to make wedding planning less stressful.
Supernatural (The CW at 8) Jack enlists the help of a dreamcatcher named Kaia to help him save Mary Winchester.
Gotham (Fox at 8) Carmine Falcone shows up in town and Tabitha tries to get Grundy to remember his past.
Young Sheldon (CBS at 8:30) The kids think up ways to fix a family conflict.
Arrow (The CW at 9) Oliver and the team try to save Quentin Lance after he's kidnapped by Black Siren and Cayden James.
The Orville (Fox at 9) Ed and Kelly discuss trying their relationship again and the crew discovers a planet in another universe.
32 Pills: My Sister's Suicide (HBO at 8) Hope Litoff investigates her sister's mental illness and eventual suicide.
Pysch: The Movie (USA at 8) A holiday movie based on the show, in which an amateur sleuth tricks a police force into hiring him after convincing them that he has psychic powers.
Conan (TBS at 11) Patton Oswalt, Andy Serkis, Royal Blood.
Daily Show (Comedy Central at 11) Tiffany Haddish.
Colbert (CBS at 11:35) Sarah Paulson, John Hodgman, Bobby Flay.
Kimmel (ABC at 11:35) Octavia Spencer, Dave Franco, Hanson, Melissa McCarthy.
Fallon (NBC at 12:05) James Franco, Niall Horan.
Corden (CBS at 12:37) Kobe Bryant, Morgan Freeman, Glen Keane.
Meyers (NBC at 1:07) Wendy Williams, Mike Birbiglia, Brooks Wackerman.