Mariah Carey is among the many stars in the holiday spirit this year. She Instagrammed about loving onesies, adding, "It's Christmastime!"
Click through for photos of Duchess Kate, Britney Spears, John Legend and more.
Credit: Mariah Carey/Instagram
Taylor Swift
Taylor Swift posed with her beau, Calvin Harris, in this winter pic, posted shortly before Christmas. She captioned it: "Really proud of ourselves over here."
Credit: Taylor Swift/Instagram
Reese Witherspoon
Reese Witherspoon is in the giving spirit this year: "Think I got just about everyone...Have y'all finished your Christmas shopping yet? (this @draperjamesgirl wrapping paper.)," she wrote alongside this festive shot on Instagram.
Credit: Reese Witherspoon/Getty Images
Troy Brown
New England Patriots alumnus Troy Brown gifts a football to guest conductor Trey at The Boston Pops holiday performance at Boston Children's Hospital Dec. 22, 2015, in Boston,
Credit: Darren McCollester/Getty Images
Taylor Swift
Taylor Swift posted this Instagram photo of her dad ahead of Christmas with the caption: "Scott Swift decorating the tree."
Credit: Taylor Swift/Instagram
Ariel Winter
Actress Ariel Winter got into the holiday spirit this year. "This is why I don't do blind dates. I need new wingmen," she wrote on Instagram.
Credit: Ariel Winter/Instagram
Chrissy Teigen
Model Chrissy Teigen showed off her dog in this adorable Santa-themed photo on Instagram.
Credit: Chrissy Teigen/Instagram
Tiffani Thiessen
"Our festive holiday cards are designed by my talented sis n law @jillsmithdesign for@tinyprints, she wrote, adding "#holidaysarehere#ilovemyfamily" actress Tiffani Thiessen Instagrammed.
Credit: Tiffani Thiessen/Getty Images
Sarah Michelle Gellar
"@lancebass I think we might win the #uglysweater couple contest (is there one?)," actress Sarah Michelle Gellar wrote on Instagram, alongside a photo with Lance Bass.
Credit: Sarah Michelle Gellar/Instagram
Justin Bieber
Justin Bieber posted this pic on Instagram with the simple caption: "Merry Christmas."
Credit: Justin Bieber/Instagram
Kelly Clarkson
Kelly Clarkson shared this "Game of Thrones" Christmas card on Instagram, writing, "Merry Christmas from the Blackstock clan! @gameofthrones #gameofthrones #winteriscoming #riverisnotworried"
Credit: Kelly Clarkson/Instagram
Kim Kardashian
This elaborate Christmas tree set-up was posted by Kim Kardashian on Instagram with the caption: "Candy Cane Lane Kris Jenner Style"
Credit: Kim Kardashian/Instagram
Prince Harry
Prince Harry's 2015 Christmas card features a black-and-white photo of Harry with 95-year-old Tom Neil, the last surviving Royal Air Force pilot from the Battle of Britain.
Credit: Prince Harry/Kensington Palace
Princess Charlene & Prince Albert II
Princess Charlene of Monaco and Prince Albert II of Monaco attend the Christmas gifts distribution on Dec. 16, 2015, in Monaco.
Credit: Pascal Le Segretain/Getty Images
Duchess Kate
Britain's Catherine, Duchess of Cambridge, takes part in group activities as she attends the Anna Freud Centre Family School Christmas Party at Anna Freud Centre, in London, Dec. 15, 2015.
Credit: Chris Jackson/Reuters
Duchess Kate
Catherine, Duchess of Cambridge, attends the Anna Freud Centre Family School Christmas Party at Anna Freud Centre on Dec. 15, 2015, in London. She joined groups of families in festive activities designed to help students reflect on the positive progress in their social relationships and communication skills.
Credit: Chris Jackson/Getty Images
Duchess Kate
Catherine, Duchess of Cambridge, attends the Anna Freud Centre Family School Christmas Party at Anna Freud Centre on Dec. 15, 2015, in London.
Credit: Chris Jackson/Getty Images
Miranda Kerr
Australian actress and model Miranda Kerr poses for photographers during a Christmas tree lighting ceremony in Tokyo on Dec. 13, 2015.
Credit: Toru Yamanaka/AFP/Getty Images
Jewel
Jewel performs during "Let It Snow" SiriusXM Acoustic Christmas at SiriusXM Music City Theatre on Dec. 14, 2015, in Nashville, Tennessee.
Credit: Rick Diamond/Getty Images
Kylie Minogue
Australian singer Kylie Minogue, right, poses with her waxwork in a Christmas special during a photocall at Madame Tussauds in London on Dec. 8, 2015.
Credit: Ben Stansall/AFP/Getty Images
Kendra Wilkinson
Kendra Wilkinson attends Knott's Merry Farm Countdown to Christmas & Tree Lighting at Knott's Berry Farm on Dec. 5, 2015, in Buena Park, California.
Credit: Jerod Harris/Getty Images
Jodie Sweetin
Actress Jodie Sweetin attends Knott's Merry Farm Countdown to Christmas & Tree Lighting at Knott's Berry Farm on Dec. 5, 2015, in Buena Park, California.
Credit: Jerod Harris/Getty Images
Alison Sweeney
Actress Alison Sweeney attends Knott's Merry Farm Countdown to Christmas & Tree Lighting at Knott's Berry Farm on Dec. 5, 2015, in Buena Park, California.
Credit: Jerod Harris/Getty Images
John Legend
Singer/songwriter John Legend performs his new holiday song, "Under the Stars," written exclusively for Stella Artois, in New York City, on Dec. 9, 2015.
Credit: Mike Coppola/Getty Images
Cody Simpson
Musician Cody Simpson of Coast House performs at Hollister's Holiday Carnival with Coast House at The Roxy Theatre on Dec. 9, 2015, in West Hollywood, California.
Credit: Jesse Grant
Michael Bublé
Michael Bublé performs during the 83rd Annual Rockefeller Center Christmas Tree Lighting Ceremony on Dec. 2, 2015, in New York.
Credit: Brad Barket/Invision/AP
Cole Whittle
Musician Cole Whittle of DNCE performs onstage during Z100's Jingle Ball 2015 at Madison Square Garden on Dec. 11, 2015, in New York.
Credit: Mike Coppola/Getty Images
Fifth Harmony
From left, Lauren Jauregui, Ally Brooke, Dinah-Jane Hansen, Camila Cabello and Normani Hamilton of Fifth Harmony perform during Z100's Jingle Ball 2015 at Madison Square Garden on Dec. 11, 2015, in New York.
Credit: Mike Coppola
Selena Gomez
Singer Selena Gomez performs onstage during Z100's Jingle Ball 2015 at Madison Square Garden on Dec. 11, 2015, in New York.
Credit: Larry Busacca/Getty Images
Shay Mitchell
Actress Shay Mitchell attends the Delta Air Lines Hosts Fifth Annual "Holiday In The Hanger," a special holiday celebration for Children's Hospital Los Angeles and P.S. Arts at LAX Airport on Dec. 2, 2015, in Los Angeles.
Credit: Jason Kempin/Getty Images
Andy Grammer
Andy Grammer performs during the 83rd Annual Rockefeller Center Christmas Tree Lighting Ceremony on Dec. 2, 2015, in New York.
Credit: Brad Barket/Invision/AP
Sting
Singer Sting performs at the lighting ceremony for the 83rd Rockefeller Center Christmas tree at Rockefeller Center in the Manhattan borough of New York, Dec. 2, 2015.
Credit: Lucas Jackson/Reuters
Band Of Merrymakers
Musicians Tyler Glenn, left, and Sugar Ray's Mark McGrath of Band Of Merrymakers perform onstage during the 2015 Hollywood Christmas Parade on Nov. 29, 2015, in Hollywood, California.
Credit: Mike Windle/Getty Images
Kat Graham
Singer/actress Kat Graham and Santa attend 2015 Hollywood Christmas Parade on Nov. 29, 2015, in Hollywood, California.
Credit: Alberto E. Rodriguez/Getty Images
Britney Spears
Singer Britney Spears arrives at a Christmas tree-lighting ceremony at The LINQ Promenade on Nov. 21, 2015, in Las Vegas, Nevada.
Credit: David Becker/Getty Images
Tori Spelling
"I am SO excited about this year's holiday card! We used SimplytoImpress.com again this year because their designs are fab & prices are amazing. What do you think?!" Tori Spelling wrote on Instagram with her a picture of her 2015 holiday card.
Credit: Tori Spelling/Instagram
Miley Cyrus
Miley Cyrus snuggled up next to her dog, Emu, and wore a modern take on the Christmas sweater.
Credit: Miley Cyrus/Instagram
Selena Gomez
Sure looks cozy! Selena Gomez posted a photo of herself cuddling with an adorable baby.
Credit: Selena Gomez/Instagram
The Kardashians
Kim Kardashian West posted a cute throwback photo of herself with sisters Kourtney and Khloe Kardashian. She captioned the photo "1986 Christmas."
Credit: Kim Kardashian West/Instagram
Kevin Hart
Comedian Kevin Hart and his kids clowned around in their matching onesies. Hart wrote on Instagram, "Onesie Thuggin with my silly ass Kids....The apple doesn't fall far from the tree I guess."
Credit: Kevin Hart/Instagram
Sam Smith
Sam Smith says it's time for him to rest up, and obviously, the best place to sleep is right by the presents. He wrote on Instagram, "Christmas Eve eating and snuggles begin. Time to lay on the sofa like a beached whale for the next week. I'm going IN."