What’s On Tonight: The Season 20 Finale Of ‘South Park’ Is Here And So Is ‘Hairspray Live!’

South Park (Comedy Central, 10:00 p.m.) — In the season finale, Cartman finally learns why Heidi wants to go to Mars and Kyle and Ike rally the kids to save the world.

Hairspray Live! (NBC, 8:00 p.m.) — NBC is bringing another famous Broadway musical to the small screen tonight with Hairspray Live!. The story’s the same — teen girl wants to dance on a famous TV show, ends up fighting for civil rights, hooking up with the guy of her dreams and getting to dance on said TV show — but some famous faces are suiting up for this one. Kristin Chenoweth; Ariana Grande; Harvey Fierstein; Jennifer Hudson; and Martin Short are all involved.

Arrow (CW, 8:00 p.m.) — After an attack on Curtis, Oliver realizes that their foe Prometheus knows all of the team’s secret identities and is targeting them one by one. Elsewhere, Felicity works with Det. Malone to discover more about Prometheus including his link to Oliver’s past.

Lethal Weapon (Fox, 8:00 p.m.) — Murtaugh and Riggs plan a nice holiday that is quickly sidelined thanks to a homicide linked to the deranged nephew of a drug lord who has a history with Riggs. (This guy has a colorful past.) While Riggs deals with memories of Christmases past with his dead wife, Murtaugh confronts his neighbors about their obnoxious holiday decorations.

Survivor: Millennials vs. Gen X (CBS, 8:00 p.m.) — Immunity is on the line in a classic game of pinball and two castaways are sent to the jury during two separate tribal councils.

The Goldbergs (ABC, 8:00 p.m.) — Beverly plans Murray’s surprise 50th birthday party against his wishes and Barry challenges Adam to a battle at the school gym after Adam becomes obsessed with imitating the Globetrotters.

Speechless (ABC, 8:30 p.m.) — Maya and Kenneth bond during a CPR class while JJ tries to convince Jimmy to let him play sled hockey.

Criminal Minds (CBS, 9:00 p.m.) — The remains of a dozen people are found near a creek in Yakima, Washington so the team travels there to investigate.

Empire (Fox, 9:00 p.m.) — Jamal begins working with Phillip, hoping their collaboration will finally cure him of his PTSD. Meanwhile, Tariq and Leah work together to bring down Lucious and Andre sabotages Tiana’s appearance at a fashion show in order to get Nessa into the spotlight.

Frequency (CW, 9:00 p.m.) — Frank is blindsided by a terrible portrayal and he and Raimy discover a shocking secret about the Nightingale.

Vikings (History, 9:00 p.m.) — Ragnar has trouble rounding up a crew to sail with him to Wessex which prompts Kattegat locals to believe that the gods have deserted him. Meanwhile, Bjorn’s dream to explore the Mediterranean is within reach but first he has to bargain with a familiar face.

Blackish (ABC, 9:30 p.m.) — Zoey needs an internship for school so she asks Dre to use his connections to get her one at Teen Vogue — he does, but only after finding out that Bow has gotten her a job at the hospital.

Code Black (CBS, 10:00 p.m.) — When a 13-year-old girl comes into the hospital after a seizure caused by spina bifida the doctors are stunned to find out that she’s Campbell’s daughter.

Designated Survivor (ABC, 10:00 p.m.) — President Kirkman deals with yet another threat, this time from a group of hackers who have leaked classified information to the public and are currently holed up in an embassy beyond his reach. Elsewhere, Hannah is running out of time to prove MacLeish’s involvement in the conspiracy before his confirmation as vice president.

Incorporated (Syfy, 10:00 p.m.) — Theo is forced to cage fight; Ben tries to deflect suspicion after the Spiga data breach; and Laura helps an inncent family after her mother evicts them.

Conan (TBS, 10:00 p.m.) — Conan is heading to Berlin in this early special of his late night talk show. Watch him drive on the autobahn, master “schuhplattler” and gets left in a brothel with a dominatrix. Here’s hoping he remembers his safe word.

Younger (TV Land, 10:00 p.m.) — Liza and Josh have a near miss, but react very differently, which puts their relationship in doubt.

Legends of Chamberlain Heights (Comedy Central, 10:30 p.m.) — Grover’s ready for his big moment after the team’s star player is injured just before the tournament by a citywide blackout causes the gym to go dark and might ruin his chance in the spotlight.

LATE NIGHT GUESTS

Jimmy Kimmel Live!: Ryan Gosling, T.J. Miller, Pentatonix

The Tonight Show Starring Jimmy Fallon: Edward Norton, Riz Ahmed, Nintendo President Reggie Fils-Aime

The Late Show With Stephen Colbert: Sigourney Weaver, Andy Cohen, Pilobolus

Late Night With Seth Meyers: Rita Ora, Kacey Musgraves, Abe Cunningham

The Late Late Show With James Corden: Lily Tomlin, Alison Sudol, Reggie Watts

The Daily Show With Trevor Noah: Brian Tyree Henry

Conan: Melissa Rauch, Robert Glasper Experiment