Late night’s most elfin figure, Conan O’Brien, hosts “Christmas in Washington” (7 p.m., TNT), an annual holiday festival now celebrating its 30th anniversary.

Speaking of elves, O’Brien will be joined by singer Justin Bieber, the boyish north-of-the-border singer/celebrity, whose Christmas album, “Under the Mistletoe,” is now in music stores — both the bricks-and- mortar and digital varieties. Cee Lo Green, singer/rapper and host of “The Voice,” will also perform songs of the season, as will Oscar-winning “American Idol” contestant Jennifer Hudson and cable TV star Victoria Justice (“Victorious”). And country group The Band Perry round out the roster for this hourlong event that has appeared on TNT since 1999.

• Also in a festive mood, Fox repeats three animated holiday offerings: the new Peanuts special, “Happiness Is a Warm Blanket, Charlie Brown” (7 p.m.); “Ice Age: A Mammoth Christmas” (8 p.m.), featuring the voice of Ray Romano; and the latest Christmas episode of “The Simpsons” (8:30 p.m.), in which a grown-up Bart and Lisa, now in their late 30s, glance back at their childhoods. And that’s no mean feat, given that they’ve been children for more than 20 years!

• While not exactly holiday-themed, ABC Family offers two highly acclaimed cartoons, one an old-fashioned, 2-D favorite, and the other an excellent example of the CGI genre. Listen for the late Jerry Orbach (“Law & Order”) as the candlestick in the 1991 musical “Beauty and the Beast” (6 p.m.). A crotchety widower with Ed Asner’s voice (and more than a touch of Spencer Tracy’s personality) takes a boy aloft in the long-postponed adventure of a lifetime in the much-admired 2009 Pixar feature “Up” (8 p.m.).

• Also on the animated front, HBO launches the third season of “The Life & Times of Tim” (8 p.m.). Unlike many cartoon comedies that use animation to go places and show things that would be impossible in the live-action realm, “Tim” remains decidedly modest in its narrative ambitions, centering around a sad-sack’s strenuously modest existence. I have never much seen the humor, nor the point of “Tim,” and I don’t think I’m alone.

Tonight’s other highlights

• An Alabama event planner crafts memorable evenings on the new six-part series “Bama Glama” (7 p.m., Food).

• Mistaken identity on “Chuck” (8 p.m., NBC).

• A murder in the woods seems familiar on “Grimm” (8 p.m., NBC).

• “Great Performances” (8 p.m., PBS) presents “The Little Mermaid From San Francisco Ballet.” Check local listings.

• A clean cut for a change on “Gold Rush” (8 p.m., Discovery).

• Friendly fire brings official scrutiny on “Blue Bloods” (9 p.m., CBS).

• Scheduled on “20/20” (9 p.m., ABC): The Million Moms Challenge on Maternal Health.