STAR SIGHTINGS: Kristen Stewart, Jon Hamm, Mary J. Blige and More Take Over Sundance -- See the Pics!
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Happy Birthday, Mary J. Blige!

The "No More Drama" singer celebrated her 46th birthday with close friends and family at a private residence in Deer Valley, Utah, on Jan. 20. Guests included Aisha Tyler, DJ Nice, Jason Mitchell, and her sister, Latonya Blige. The party was catered by The Hudson restaurant, which provided tasty bites like quinoa bowls, skirt steak and street corn. Those in attendance sipped on D'usse mixed cocktails and feasted on a delicious cake emblazoned with "Happy Birthday Queen."

PHOTOS: Star Sightings at the 2017 Sundance Film Festival

Michael Kovac
Earlier in the day, Jon Hamm was spotted in Park City, Utah, promoting his latest film, Marjorie Prime. The 45-year-old actor took time off his busy schedule to stop by the Variety Studio at Sundance to get acquainted with the new Google Home, a voice-activated speaker designed to play any song in the world. Hamm's tune of choice was "Rhapsody in Blue" by George Gershwin.
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With four films scheduled to hit theaters this year, Kristen Stewart was all smiles while promoting a variety of projects at Sundance in Park City, Utah, on Jan. 20. One of her first stops, IMDb Studio's Filmmaker Discovery Lounge presented by Amazon Video Direct to talk with director Kevin Smith.
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Alison Brie and her fiancé, Dave Franco, also made their way to Sundance. The two were spotted enjoying a slice of Applegate wood-fired pizza, while taking a lunch break at the Reel Food Cafe popup on Main Street on Jan. 20. The pair also enjoyed Sugarfina's Jamaican Rum Snowballs and Rosé Roses candies at The Hollywood Reporter's Sundance Lounge on Jan. 23.
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Later in the day, Jason Segel was seen enjoying a quick snack before getting back to the Sundance grind. The Discovery actor munched on Orville Redenbacher's popcorn before his interview at the Variety Studio, by The Bait Shoppe in Park City.
Dave Bautista and Pitch Perfect star Brittany Snow enjoyed a night out on Jan. 20 at XYZ Films Sundance Party presented by Maestro Dobel Tequila. The two are currently promoting their new film, Bushwick, currently out in theaters.
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Chelsea Handler, who organized the Women’s March in Park City on Saturday, partied with Aisha Tyler and Joshua Jackson following the march at TAO Park City presented by Tequila Don Julio. The crowd enjoyed a special performance by Common, who hit the stage to perform “Go” and freestyled to Kanye West’s “Fade.”
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Al Powers/Powers Imagery
Later in the week, Woody Harrelson and musician Bob Weir celebrated the premiere of Long Strange Trip by teaming up to perform a few songs at Amazon Studios on Jan. 22.
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Jason Ritter, who premiered his film, Bitch, at Sundance, attended Debbie Durkin’s 10th Annual EcoLuxe Lounge sponsored by Choices Recovery and Shriners For Children Medical Center in Park City on Jan. 25.
Over on the West Coast, Chantel Jeffries helped celebrate the new L.A. Hearts Spring 2017 Swimwear collection with Pacsun during a private dinner party at celeb hot spot Delilah in West Hollywood, California, on Jan. 25.
Later in the week, Alessandra Ambrosio was spotted out in Los Angeles heading to a yoga class wearing an Old Navy Women's Go-Dry mesh-trim sweatshirt and Go-Dry mid-rise printed compression leggings.
Michael Simon
Hall of Fame wide receiver Jerry Rice and his dog, Simba, teamed up with PEDIGREE® to get in the Puppy Bowl spirit.
Michael Simon
Snoop Dogg was on hand this week to help celebrate the launch of Tanqueray No. TEN™ in Los Angeles.
Michael Simon
Miss Universe 2015 Pia Wurtzbach stopped by Amazon’s Style Code Live fashion show on Jan. 24 to talk about her beauty secrets and YouTube channel.
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Christina Milian joined forces with JetSmarter for an exclusive VIP event on Jan. 18 to celebrate the launch of its services in Atlanta, Georgia. Milian mingled with guests inside the Hawthorne Hangar at the Cobb County Airport, where guests were able to get an inside look at the luxurious jets that JetSmarter will be using on flights to top cities across the United States.
Dancing With the Stars pro Louis van Amstel and his husband, Josh Lancaster, continued celebrating their nuptials at Pritikin Longevity Center + Spa in Miami, Florida, on Jan. 19. During their trip, Amstel hosted a special fitness dance class, titled LaBlast with a Star.
Also spotted on the East Coast was Saleka Shyamalan, daughter of filmmaker and Pennsylvania resident M. Night Shyamalan, who performed the national anthem at the Philadelphia 76ers game on Jan. 24.
On Thursday, Kathryn Hahn helped launch Febreze's new "Odor Odes" campaign in New York City. Consumers can share their own #OdorOdes stories at www.OdorOdes.com.
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Check out even more star sightings in the gallery below.