WHITE COLLAR: Peter worries Neal while working on an unsolved larceny case. (David Giesbrecht/USA Network)

FINALE WATCH: Host Mario Lopez will crown a new winner on the live Season 3 finale of “The X Factor” (Fox at 8 p.m.). The two-hour show will feature performances from Lea Michele, One Direction, Mary J. Blige and Leona Lewis.

The judges select songs to be performed by the final four groups on the latest “The Sing-Off” (NBC at 8).

Robin Roberts anchors “The Year” (ABC at 9), a retrospective on the biggest stories of 2013 that include the Cleveland kidnappings, the trials of Jodi Arias and George Zimmerman, the election of Pope Francis, the Boston Marathon bombing and the birth of Prince George.

The designers are asked to identify a new fashion trend for 2014 with help from influential bloggers on “Project Runway All Stars” (Lifetime at 9). Nina Garcia, Christian Siriano and Francisco Costa are guest judges.

Patti tries to find love for fashionista and reality star Courtney Kerr of “Courtney Loves Dallas” fame on “The Millionaire Matchmaker” (Bravo at 9), while the other client looking for love is a clothing-line owner.

Peter investigates an unsolved larceny case on “White Collar” (USA at 9), which worries Neal, given that he is actually responsible for the crime.

On a sentimental look back on the series, the guys get together for a Christmas barbecue on “Pawn Stars: A Very Vegas Christmas” (History at 9), where a debate arises on what the best and worst deals the crew has ever made would be.

A surprise wedding in the United Kingdom turns a family holiday into a honeymoon on the “Gypsy Sisters” special “A Very Merry Gypsy Christmas” (TLC at 10).

After trying to find love with the help of Patti Stanger on “The Millionaire Matchmaker” earlier on the network, Courtney is back on “Courtney Loves Dallas” (Bravo at 10) with a trip to New York City with her best gal pal for fashion week and a crucial meeting with a jewelry designer.

A racy bikini rodeo competition divides the women of “Rodeo Girls” (A&E at 10), while details of Marvel’s stormy past come to light.

Actor Steve Carell comes to “The Late Show With David Letterman” (CBS at 11:35), with musical guests the Saint Johns.

Actor Sylvester Stallone and producer Judd Apatow join “The Tonight Show With Jay Leno” (NBC at 11:35), with vocal group Libera.

Comedic actors Will Ferrell and Adam Scott are on “Jimmy Kimmel Live” (ABC at 11:35), with music from Christopher Cross featuring Ron Burgundy.

— Rachel Lubitz