Kelly Clarkson, Brad Paisley, Rihanna & Sophia Bush Get in the Halloween Spirit -- Plus, More Star Sightings!

Kelly Clarkson at iheartradio album release party
Joseph Llanes

See how the A-listers have been living it up this Halloween season!

There's nothing like Halloween in Hollywood!

Stars went all out celebrating the spookiest day of the year -- not just on Oct. 31, but for practically the whole week leading up to it!

Kelly Clarkson kicked off Halloween weekend with her iHeartRadio Album Release Party at the iHeartRadio Theater in Burbank, California, on Oct. 27. The live event included a Q&A session as well as a performance, where she sang a few of her new songs like “Love So Soft” and “Heart,” as well as her classics, including “Because of You” and “Breakaway.”

Kevin Winter/Getty Images for iHeartMedia

Brad Paisley and Kimberly Williams-Paisley put on costumes to host a family-friendly VIP gaming event with Xbox for their fellow country music artists, athletes and other Nashville celebrities including Cassadee Pope, John Rich, Mat Kearney, Rodney Atkins and Little Big Town. They got to play quite a few different games, including Minecraft, Just Dance 2018, Zoo Tycoon and Madden NFL 18.

John Shearer/Getty Images for Xbox

Sophia Bush hosted the fifth annual UNICEF’s Next Generation Masquerade Ball at Clifton’s Republic in Los Angeles on Oct. 27.

Getty Images

Dressed as Star Wars villain Kylo Ren, Rihanna and her boyfriend, Hassan Jameel, celebrated Halloween night at Lucky Strike Boston. The pair were joined by two costumed friends as they bowled on four lanes for over an hour and munched on an appetizer sampler that included buffalo wings, mozzarella sticks and coconut shrimp. RiRi topped the scoreboard with several strikes and even took the time to autograph one of the bowling lane’s signature pins while at the venue.

Lucky Strike Boston

On Mischief Night, Tara Reid celebrated the release of her new movie, Party Bus to Hell, with the cast and crew at The Golden Tiki in Las Vegas. The American Pie alum wore a shimmery fringe dress with revealing cutouts while enjoying one of the tiki bar’s famous Dole Whips, as well as the Tiki Punch and Mai Tais.

Rita Ora, The Butter Group's Richie Akiva and Charli XCX struck a pose at 1Oak, Up&Down and Spring Studios/Spring Place's Halloween after-party for the Naked Heart Foundation and AMFAR’s Fabulous Fund Fair in New York City on Oct. 28, where guests enjoyed drinks by Dom Perignon, Ciroc and Deleon Tequila.

Matteo Prandoni/BFA.com

Corinne Olympios attended Matthew Morrison’s 8th Annual Halloween Party, presented by PAC SUN and Podwall Entertainment, at The h.wood Group’s Poppy club in Los Angeles on Oct. 28.

Vivien Best

And businesswoman Adrienne Maloof and her boyfriend, Anheuser-Busch heir Jacob Busch, hosted a Halloween party for close family and friends at Maloof’s Beverly Hills home on Oct. 28.

ETonline

Josh Duhamel celebrated Halloween a little early on Oct. 29, bringing his son, Axl, to Disneyland in Anaheim, California. An eyewitness tells ET that the 44-year-old actor was dressed in jeans, a black polo shirt and baseball cap and "appeared to be happy" as he walked around the park with his son on his shoulders.  

Despite a bone-chilling breeze and torrential downpour, Leonardo DiCaprio spent a relaxing early evening at Zuma New York in midtown Manhattan on Oct. 29. The 42-year-old actor -- who has been raising awareness for the dangers of climate change with his documentary, Beyond the Flood -- enjoyed hot pots, sushi and robata grilled fare with his friends.

One day after announcing her pregnancy, designer and influencer Chiara Ferragni hosted the first pop-up of Bershka in New York City on Oct. 27. She celebrated her Italian rapper fiance Fedez’s collection with over 300 guests, who mingled to music by DJs Mia Moretti and Jubilee and a performance by Willow Smith.

 

Griffin Lipson/BFA.com, Tiffany Sage/BFA.com

On the opposite coast, Justin Hartley and Chrishell Stause made their first post-wedding public appearance on the Febreze-scented red carpet at the Los Angeles premiere of A Bad Moms Christmas on Oct. 30.

Sayles/Invision for Febreze/AP Images

Amanda Stanton hosted Ali & Jay’s retail store grand opening at the newly opened Westfield Century City Mall in Los Angeles on Oct. 26. The Bachelor in Paradise star, who sweetly took photos with fans, stunned in at St. Tropez two-piece set from Ali & Jay. Glamsquad was on site providing guests with dry styling, while Gold Frame Media provided a photo booth capturing chic black-and-white “Kardashian-style” filtered photos.

Brittney Christie

Along with keynote speakers Chelsea Handler, Anita Hill and Jordan Peele, Geena Davis was among the stars who took the stage at Variety’s Inclusion Summit, presented by Mercedes-Benz, at the Montage Beverly Hills on Nov. 1. The annual one-day summit is an elite gathering of leaders and innovators who support film, TV and digital media that reflect different genders, disabilities, sexual identities, ethnicities and ages.

Variety/REX/Shutterstock

Nearby, Sofia Vergara was by husband Joe Manganiello’s side when he was honored at the Peggy Albrecht Friendly House 28th Annual Awards Luncheon at The Beverly Hilton Hotel in Beverly Hills on Oct. 28.

Vince Bucci

Gregg Sulkin was at an awards show as well, looking quite dapper at BAFTA’s Britannia Awards on Oct. 27, where Ruffino Wines was being served.

Vivien Best/Getty Images

There was plenty of giving back as well. Carnie Wilson joined forces with celebrity chefs Melissa d’Arabian, Simon Majumdar and Aarti Sequeira for a friendly cook-off on Oct. 29 that helped raise funds for the United Cerebral Palsy of Los Angeles.

JeremyLeePhoto.com

Plus, Milck couldn’t keep quiet at her private performance in Los Angeles on Nov. 1. She will release a new, empowered version of her anthem, “Quiet" -- which went viral after she sang the tune flash-mob style with a chorus during the Women’s March in Washington, D.C., earlier this year -- on Nov. 3.

Ashly Covington

Clad in a funky Marcell von Berlin dress and strappy Giuseppe Zanotti sandals, Alessandra Ambrosio stood out at Perrier-Jouet’s Garden of Wonder, hosted by Simon Hammerstein in West Hollywood on Oct. 26. She sat at a private table with newly single Elon Musk and her fellow Victoria's Secret model, Jessica Hart. Usher was there as well, rocking a mirrored mask and snapping photos in a life-sized birdcage while enjoying champagne.

Stefanie Keenan/Getty Images for Perrier-Jouet

Meanwhile, Christina El Moussa showed off her Mother Trucker hat that read "namaste" while in a convertible, posting the pic to her Instagram Story on Oct. 30.

Click through the gallery below for even more must-see star sightings.