Katy Perry and Lady Gaga Reunite in L.A., Plus Camila Cabello, Shawn Mendes and More

Billie Eilish performs onstage during the 2021 Governors Ball Music Festival in New York City on Sept. 24.

Katy Perry and Lady Gaga share a sweet moment while attending the opening gala for the Academy Museum of Motion Pictures in Los Angeles on Sept. 25.

Camila Cabello and Shawn Mendes gaze lovingly into each other's eyes during their performance at Global Citizen Live in New York on Sept. 25.

Jonathan Scott and Zooey Deschanel pose for a photo with Goofy, Donald Duck and Pluto while enjoying the Halloween Time festivities at Disneyland Park in Anaheim, Calif., on Sept. 25.

Sarah Michelle Gellar sports mouse ears in Cars Land while celebrating Halloween Time at Disneyland Park in Anaheim, Calif., on Sept. 25.

Ricky Martin performs onstage at the MGM Grand Garden Arena during his concert with Enrique Iglesias (not pictured) in Las Vegas on Sept. 25.

Dua Lipa celebrates with fashion designer Donatella Versace after making her runway debut on Sept. 24 in Versace's Spring/Summer 2022 show during Milan Fashion Week.

Katie Holmes poses on the red carpet at the opening night screening of The Tragedy of Macbeth on Sept. 24 during the New York Film Festival.

Jennifer Lopez is ready for fall in a fur coat and black leggings in N.Y.C. on Sept. 24.

Mickey Guyton celebrates her album release with a performance during the Citi Music Series on Today in New York City on Sept. 24.

Lourdes Leon hits the catwalk on Sept. 24 during the Versace show at Milan Fashion Week in Italy.

Chanel Iman brings daughters Cali and Cassie as American Girl celebrates its 35th anniversary and the debut of World by Us at a fashion show event in partnership with Harlem's Fashion Row in N.Y.C. on Sept. 23.

Pete Wentz shows off his long blond locks during a coffee run in Los Angeles on Sept. 24.

Rihanna arrives in style to a party in New York City on Sept. 24 following her Savage X Fenty Show Vol. 3.

Sam Trammell joins a crowd on Sept. 23 to help clean up Huntington Beach, California, with the Shiseido Blue Project in partnership with World Surf League PURE and WILDCOAST.

Normani defies gravity on Sept. 23 while performing at Rihanna's Savage X Fenty show Vol. 3 presented by Amazon Prime Video at The Westin Bonaventure Hotel & Suites in Los Angeles.

Joshua Jackson and Jodie Turner-Smith get all glammed up for an evening out in Milan, Italy, on Sept. 23.

Madonna gets some love from boyfriend Ahlamalik Williams at the world premiere of her Madame X, presented by Ketel One Vodka, at the Paradise Club & Theater at The Edition Hotel Times Square in N.Y.C. on Sept. 23.

Also there: Christian Siriano and Drew Barrymore, who buddy up on the red carpet.

Camila Cabello goes glam on Sept. 23 for the 2021 Billboard Latin Music Awards in Coral Gables, Florida.

Prince Albert II of Monaco greets Sharon Stone and Orlando Bloom at the 5th Monte-Carlo Gala for Planetary Health in Monaco on Sept. 23.

Kate Middleton reaches for the shot on Sept. 24 as British US Open champions Emma Raducanu, Joe Salisbury, Gordon Reid and Alfie Hewett return to the LTA's National Tennis Centre for a celebration in London.

The Weeknd shows off his new hardware on Sept. 23 after accepting the Quincy Jones Humanitarian Award from the Black Music Action Coalition at the Music in Action Awards at 1 Hotel West Hollywood.

Snoop Dogg performs at the world premiere screening and concert for Starz's new series BMF on Sept. 23 at Cellairis Amphitheatre in Atlanta.

Megan Fox gets all dressed up for a coffee run in New York City on Sept. 23.

Chris Martin and Coldplay take the stage at New York City's Apollo Theater for the SiriusXM and Pandora Small Stage Series on Sept. 23.

Louis Eisner and Ashley Olsen coordinate in black on Sept. 23 for the YES 20th Anniversary Gala in Los Angeles.

Jessica Chastain continues her international style streak on Sept. 23 while arriving to her hotel ahead of the 69th San Sebastian International Film Festival in Spain.

Derek Hough shows off his toned physique on Sept. 22 as he opens his new residency show, Derek Hough: No Limit, at The Venetian Resort in Las Vegas.

Addison Rae falls for florals on Sept. 23 while arriving to a show at Milan Fashion Week in Italy.

A masked Justin Theroux hops on his bike for a ride in New York City on Sept. 23.

Prince William, president of the Football Association, visits Dulwich Hamlet FC at the Champion Hill Stadium in London on Sept. 23 to talk to various clubs about a recent fan-led review of football governance.

Maria Bakalova gives the cameras a look on Sept. 23 on the Venice, Italy, set of her new film The Honeymoon.

Bella Thorne and Benjamin Mascolo cozy up ahead of the Etro fashion show during Milan Fashion Week in Italy on Sept. 23.

Shanina Shaik stepped out Thursday night to celebrate the launch of TWENTY Montreal's SoHo store in N.Y.C.

Backstage, Irina Shayk gets fitted for a look at the Etro show during Milan Fashion Week.

Katie Couric and husband John Molner (far right) stop by a public exhibit by photographers and ocean conservationists Paul Nicklen and Cristina Mittermeier in partnership with digital platform Only One and SeaLegacy at NeueHouse in N.Y.C.

Mariska Hargitay and Christopher Meloni share one of their signature sweet moments on NBC's Today on Sept. 23 in N.Y.C. while promoting the upcoming seasons of Law & Order: Special Victims Unit and Law & Order: Organized Crime.

Julianne Moore turns it out on Sept. 22 for a visit to Jimmy Kimmel Live! in L.A.

Cynthia Erivo has the spotlight on Sept. 22 while performing on The Tonight Show in N.Y.C.

The Fugees — Lauryn Hill, Wyclef Jean and Pras — have their much-anticipated reunion on Sept. 22 on The Rooftop at N.Y.C.'s Pier 17.

Prince Harry and Meghan Markle kick off their New York City visit on Sept. 22 with a trip to One World Observatory at the World Trade Center.

Natalie Hemby, Amanda Shires, Maren Morris and Brandi Carlile of The High Women join singer Yola at the 20th Annual Americana Honors & Awards at Nashville's Ryman Auditorium on Sept. 22.

Sofia Richie has a health day out at the Gymshark Retreat Event in Malibu to celebrate Whitney Simmons' third collaboration with the activewear brand.

Gigi Hadid leads the bright orange charge on Sept. 23 at the Boss fashion show in Milan, Italy.

Michael Gandolfini and Alexandra Intrator get their moment on Sept. 22 at the New York City premiere of The Many Saints of Newark.

Emily Ratajkowski keeps her cool on Sept. 22 in N.Y.C. with a black cropped turtleneck and leather pants.

Anderson Cooper holds his new tome on Sept. 22 ahead of an interview on SiriusXM in New York City.

Ben Platt and boyfriend Noah Galvin make their red carpet debut on Sept. 22 at the Los Angeles premiere of Platt's movie Dear Evan Hansen.

Queer Eye's Antoni Porowski visits the top of the Empire State Building to mark Hunger Action Month in N.Y.C. on Sept. 22.

Bebe Rexha adds a pop of pink to her ensemble for dinner at Giorgio Baldi in Santa Monica on Sept. 22.

Jamie Lee Curtis hangs with godson Jake Gyllenhaal on Sept. 21 at a special screening of his film The Guilty at the San Vicente Bungalows in L.A.

Gigi Hadid walks the runway at the Alberta Ferretti fashion show during Milan Fashion Week in Italy on Sept. 22.

Ciara slips into her fall best on Sept. 22 to check out her Lita by Ciara clothing line at Nordstrom in N.Y.C.

John Legend gets down on Sept. 21 during his show at L.A.'s Greek Theatre.

Sophia Bush, Billie Jean King and Nia Batts join Chicago Mayor Lori Lightfoot (second from left) in opening the First Women's Bank flagship — the only women-founded, women-owned and women-led commercial bank in the country — in Chicago on Sept. 22.

Rihanna celebrates her Savage X Fenty Vol. 3 show in Los Angeles on Sept. 21 with a star-studded red carpet ahead of the runway show.

Shawn Mendes is happy to hang on Sept. 21 at the SoulCycle and
Flow Sustainability Event for Climate Week at a SoulCycle in N.Y.C.'s NoHo neighborhood.

Constance Wu looks ready for spring on Sept. 21 while shooting Lyle, Lyle, Crocodile in N.Y.C.

Lily Collins and husband Charlie McDowell get all dressed up for the Clash de Cartier event in Berlin on Sept. 21.

Yolanda Hadid joins son Anwar and his girlfriend Dua Lipa for a walk in New York City on Sept. 21.

Kathy Hilton is flanked by daughters Paris and Nicky on Sept. 21 at the 16th annual toy drive for Children's Hospital LA at The Abbey Food & Bar in West Hollywood.

Amanda Gorman talks up her new children's book, Change Sings: A Children's Anthem, during a visit to The Tonight Show in N.Y.C. on Sept. 21.

Mario and Courtney Lopez don denim on Sept. 21 for the grand opening of The Breakfast Club in Hollywood.

Selling Sunset's Christine Quinn goes high-fashion for a photo shoot promoting her partnership with Ciaté in London on Sept. 21.

Sophie Turner and Joe Jonas sport similar styles for a walk in New York City on Sept. 21.

Tom Hanks mans the podium on Sept. 21 at the opening of the Academy Museum of Motion Pictures in Los Angeles.

Lianne La Havas proudly shows off her award for best album on Sept. 21 at the Ivor Novello Awards in London.

Rashida Jones looks ready for fall on Sept. 21 at the COS show at The Roundhouse during London Fashion Week.

Erin O'Connor, Olga Kurylenko and Pom Klementieff brighten the night at the Richard Quinn spring/summer 2022 fashion show and cocktail party at The Londoner Hotel on Sept. 21.

John Legend gets all dressed up on Sept. 20 to celebrate the launch of his Sperry x John Legend Collection at Nordstrom at The Grove in L.A.

Hasan Minhaj greets the cameras on Sept. 20 while hitting the set of The Tonight Show in New York City.

Javier Bardem arrives with arms wide open at the premiere of The Good Boss at the 69th San Sebastian Film Festival in Spain on Sept. 21.

Jodie Whittaker smiles on set while shooting Doctor Who in Cardiff, Wales, on Sept. 20.

Ariana Grande takes a seat backstage on Sept. 20 while making her debut on NBC's The Voice from Los Angeles.

Adam Sandler keeps it neutral on Sept. 20 on the set of his Netflix film Hustle in Philadelphia.

Richie Sambora and Nile Rodgers share a moment during a concert at Bush Hall in London on Sept. 20.

The cast of ABC's Home Economics (including, from left, Jimmy Tatro, Sasheer Zamata, Karla Souza, Topher Grace and Caitlin McGee) keep it all in the (TV) family at a PEOPLE & EW-hosted drive-in screening of the show's season 2 premiere in L.A. on Sept. 20.

Neil Patrick Harris and David Burtka coordinate in shades of gray on Sept. 20 at The Public Theater's 2021 annual gala at the Delacorte Theater in New York City's Central Park.

JoJo Siwa and Jenna Johnson celebrate their Dancing with the Stars debut live from the Los Angeles ballroom on Sept. 20.

Ben Kingsley hardly looks like himself on Sept. 20 on the set of Jules in Fairfield, New Jersey.

Sabrina Dhowre and Idris Elba get all dressed up on Sept. 20 for a dinner hosted by British Vogue and Tiffany & Co. in celebration of London Fashion Week at the Londoner Hotel.

Kristin Davis has something to smile about on Sept. 20 while filming And Just Like That ... in New York City.

Mickey Mouse visits ESPN Sunday Night Baseball announcers Alex Rodriguez and Matt Vasgersian in the booth on Sept. 19 to celebrate the recent premieres of Disney Junior's series Mickey Mouse Funhouse and Marvel's Spidey and His Amazing Friends at New York City's Citi Field.

Members of BTS come together on Sept. 20 to speak and perform at the Sustainable Development Goals meeting during the 76th session of the United Nations General Assembly at United Nations Headquarters in New York City.

A casual Sophie Turner and Joe Jonas grab some juices to-go in New York City on Sept. 20.

H.E.R. and Chloe Bailey strike a pose on Sept. 19 while rehearsing for the Lights On Festival, presented by CÎROC Ultra-Premium Vodka and DeLeón Tequila, at the Concord Pavilion in California.

Minnie Driver suits up on Sept. 18 while preparing to go for a dip at the Children with Cancer UK Swim Serpentine in London's Hyde Park.

Some of the Emmys biggest names — including, from left, Jurnee Smollett, Cynthia Erivo and Lena Waite — snap a selfie with Governors Award honoree Debbie Allen on the red carpet at the Sept. 19 Emmy Awards in L.A.

Mare of Easttown's Julia Nicholson and Kate Winslet have a moment with their Emmy statuettes on Sept. 19 at the HBO and HBO Max Post-Emmys Reception at San Vicente Bungalows in West Hollywood.

Ted Lasso's Jason Sudeikis and Juno Temple celebrate their show's big night at the Emmy Awards with a small gathering at Sunset Tower in L.A. on Sept. 19.

Billie Eilish cracks a smile on Sept. 19 while performing at the Life Is Beautiful festival in Las Vegas.

Dua Lipa and Bella Hadid showcase some serious styles during a Sept. 19 stroll through New York City.

Dame Judi Dench smiles wide as she stands with Chelsea pensioners to open the Queen's Garden display during the 2021
RHS Chelsea Flower Show in London on Sept. 20.

Matilda De Angelis has some fun on the red carpet at the Nastri d'Argento film awards ceremony in Naples, Italy, on Sept. 18.

Olivia Rodrigo brings her Sour stage presence to the 2021 iHeartRadio Music Festival on Sept. 18 in Las Vegas.

Idris Elba and Sabrina Dhowre Elba attend the Roland Mouret show at the Soho Hotel during London Fashion Week on Sept. 19.

Brendan Hunt, Hannah Waddingham, Brett Goldstein, Phil Dunster and Jeremy Swift celebrate Ted Lasso at the Television Academy's Reception to Honor 73rd Emmy Award Nominees on Sept. 17 in Los Angeles.

Jessie Fisk, Nathalie Biancheri and Lily-Rose Depp take a group selfie at the premiere of Wolf at the 2021 Toronto International Film Festival on Sept. 17 in Canada.

Vanessa Hudgens kicks off Halloween season early with a visit to Knott's Scary Farm on Sept. 17.

Penélope Cruz presents Marion Cotillard with the Donostia Award during the opening gala of the San Sebastian Film Festival in Spain on Sept. 17.

Christine Chiu and Billy Porter share a special moment on the red carpet at the Elizabeth Taylor Ball to End AIDS in West Hollywood on Sept. 17.

Penélope Cruz is every bit the movie star on Sept. 17 while arriving at the 69th San Sebastian International Film Festival in Spain.

Sarah Jessica Parker travels in style on Sept. 17 on the New York City set of And Just Like That ...

Gaia Wise and Emma Thompson embrace on Sept. 17 at The Icon Ball to raise funds for NHS Charities Together and Well Child at the Landmark Hotel in London.

Pedro Pascal and a pal take a walk around New York City on Sept. 17.