Jimmy Kimmel's baby Billy had his second open heart surgery last week so the late show host had guest hosts fill in for him while he was out. Thankfully the surgery was a success and Kimmel returned to the show last night with Billy in tow to show everyone how well he is doing.

On last night's TONIGHT SHOW, music guest Niall Horan performed 'Too Much to Ask' for the studio audience. Watch the appearance below!

James Corden stopped by The Forum and gave the building's general manager a break, and proceeded to check in on Ed Sheeran, Niall Horan, Demi Lovato, Sam Smith, Liam Payne and Taylor Swift, who realizes she made a mistake in replacing a backup dancer last second.

On last night's LATE LATE SHOW, James Corden and Kristen Wiig attempted to spread some joy and holiday spirit with a duet of 'Hallelujah,' but had a hard time getting through it due to some pronunciation issues. Watch the video below!

On last night's LATE SHOW, actor Christopher Jackson, with the help of Stephen Colbert, used his Broadway talent to create a musical for the television show he's currently working on. Check out BULL: The Musical below!

On last night's LATE SHOW, indie pop act Bleachers performed 'I Miss Those Days' from their new album 'Gone Now.' Check out the appearance below!

On last night's TONIGHT SHOW, music guest Beck performed a moving rendition of 'Up All Night' off his new album 'Colors.' Watch the appearance below!

On last night's TONIGHT SHOW, guest John Cena and host Jimmy Fallon performed a dramatic holiday scene they've written together using Mad Lib words. Check out the results below!

On last night's LATE NIGHT, musical guest Hiss Golden Messenger performed 'Domino (Time Will Tell)' off his new album 'Hallelujah Anyhow.'

On last night's TONIGHT SHOW, music guest Wiz Khalifa and Ty Dolla $ign perform 'Something New' for the Tonight Show audience. Khalifa's new album drops in 2018. Watch the appearance below!

With Jimmy Kimmel off for the week, fans of JIMMY KIMMEL LIVE are in for a real treat with a whole week of famous guest hosts. To kick off the week, Chris Pratt hosted the show on Monday, interviewing stars such as Margot Robbie and Chris Stapleton.

On last night's LATE LATE SHOW, music guest Stereophonics performed 'Caught By The Wind' for the Stage 56 audience. Watch the appearance below!

On last night's LATE LATE SHOW, when Bryan Cranston sends James a custom Elf of the Shelf for the holidays, the elf's omnipresence intended to keep James honest instead drives him crazy and desperate to eliminate the elf from his life.

On last night's LATE NIGHT, musical guests Steve Earle & Lucinda Williams perform 'You're Still Standing There' off the album 'So You Wannabe An Outlaw'

On last night's TONIGHT SHOW, music guest St. Vincent performed 'Slow Disco' off the new album 'MASSEDUCATION' (pronounced 'Mass Seduction).

On last night's LATE NIGHT, musical guest Jacob Banks made his U.S. television debut performing 'Unknown (To You)'. Watch the appearance below!

On last night's TONIGHT SHOW, Grammy-winning artist Miguel parachuted into The Tonight Show to perform 'Sky Walker' off his album 'War and Leisure.' Watch the appearance below!

On last night's LATE LATE SHOW, music guest and Korean pop sensation BTS performed 'DNA' for an incredibly excited Stage 56 audience.

On last night's LATE SHOW, English alt-rock band Wolf Alice treated the audience to a performance of 'Sadboy' from their album 'Vision of a Life.' Watch the appearance below!

On last night's LATE LATE SHOW, music guest Charlie Puth performed 'How Long' for the Stage 56 audience. Watch the appearance below!

On last night's LATE LATE SHOW, James asked global superstar Kelly Clarkson to help him carpool through Los Angeles traffic while singing her classics and new music, and arranges for Kelly and her husband Brandon to have some quality time together.

On last night's TONIGHT SHOW, music guest Liam Gallagher performed the song 'Come Back to Me' from his album 'As You Were.' Watch the appearance below!

On last night's LATE NIGHT, musical guest Midland performed their son 'Make a Little' for the studio audience. The band will soon tour with Little Big Town.

On last night's TONIGHT SHOW, Martin Short and Jimmy Fallon sing a year in review of Donald Trump's controversial first term as president to the tune 'Little Drummer Boy.' Watch the performance below!

On last night's TONIGHT SHOW, music guest Spoon performs their single 'Do I Have to Talk You Into It' off of their critically acclaimed album 'Hot Thoughts' Watch the appearance below!