1. Justin Bieber
When Justin Bieber hosted Saturday Night Live in 2013, cast members Bill Hader and Jay Pharoah later revealed he was the worst host they’d ever worked with. They described him as arrogant, entitled, and dismissive toward the crew. Despite Bieber’s superstar status at the time, his behavior behind the scenes left a lasting negative impression, earning him the label of one of the rudest celebrities to ever appear on SNL.
2. Tim Allen
Casey Wilson, who starred alongside Tim Allen in The Santa Clauses, called him the “worst costar” she had ever worked with. She recalled that Allen refused to make eye contact, interrupted her during filming, and even told producers she was stepping on his lines. Wilson said his behavior was so dismissive and cold that it became her single worst acting experience, showing that even veteran actors can treat others poorly.
3. Candace Cameron Bure
JoJo Siwa famously named Candace Cameron Bure as the “rudest celebrity” she’d ever met. When JoJo was just 11, she asked the Fuller House star for a picture at a premiere, only to be brushed off. While Candace later apologized and explained it may have been a hectic red carpet moment, JoJo never forgot the sting of being rejected by someone she admired so deeply at a young age.
4. James Corden
Mel B publicly called James Corden one of the biggest “dickhead” celebrities she’s ever encountered. She pointed out his dismissive attitude toward crew members, saying he acted as if he were above everyone on set. Corden has faced similar accusations of arrogance and rudeness from other sources over the years, suggesting that his reputation for being unfriendly off-camera is more than just a one-off incident or misunderstanding.
5. Jon Hamm
Comedian Kathy Griffin revealed that Jon Hamm was shockingly rude to her during multiple encounters. At a dinner party, Hamm allegedly interrupted her conversation with Jack Nicholson, whispering insults like “You’re so old” into her ear. Griffin described him as cold, condescending, and arrogant, suggesting he believed himself to be funnier and more important than he really was. His reputation as Hollywood’s “cool guy” didn’t match her personal experiences.
6. Ashton Kutcher
Ashton Kutcher’s reputation has taken hits from multiple accounts. Kathy Griffin once claimed he ignored her at a charity event, treating her as if she wasn’t worth acknowledging. Sharon Osbourne also blasted him for having a terrible attitude and being openly disrespectful during an interview. Even radio host Fifi Box called him the “worst celebrity” she had ever met, accusing him of arrogance and dismissiveness during press interviews.
7. Lisa Kudrow
Spencer Pratt shocked fans when he revealed that Lisa Kudrow was the rudest celebrity he had ever met. At a Hollywood party, Kudrow allegedly told his wife Heidi Montag to leave him because he had “the eyes of a serial killer.” Pratt said it wasn’t a joke and left both of them stunned. Kudrow’s on-screen “Phoebe” charm from Friends clearly didn’t match Pratt’s unsettling real-life experience with her.
8. Joy Behar
Nicole “Snooki” Polizzi from Jersey Shore recalled an uncomfortable run-in with Joy Behar. She said Behar questioned her Italian heritage and mocked her reality TV background, leaving Snooki feeling disrespected. While Behar is known for her outspoken humor on The View, this encounter came off as unnecessarily rude and personal. For Snooki, it was a reminder that being in the spotlight can sometimes attract unwanted condescension from more established celebrities.
9. Ryan Reynolds
Reality TV stars Deena Cortese and Sammi “Sweetheart” Giancola said they had a less-than-pleasant experience with Ryan Reynolds. During a taping, Reynolds reportedly refused to sit near them and seemed completely uninterested in engaging. While they admitted he may have just been having a bad day, the dismissal still stung. Known as one of Hollywood’s funniest and most charming actors, Reynolds’ cold behavior was especially surprising to the Jersey Shore cast.
10. Pierce Brosnan
James Corden once revealed that Pierce Brosnan was unexpectedly rude to him at a U2 concert. According to Corden, Brosnan physically pushed him aside to get past, without apology. The brush-off was so shocking that it stuck with Corden for years. While Brosnan is often celebrated for his suave and gentlemanly James Bond persona, this incident showed a very different side of the actor in a public setting.
11. Robert De Niro
Despite his legendary status, Robert De Niro has been labeled difficult and unfriendly by several celebrities. Actor Stephen Mangan recalled a painfully awkward encounter where De Niro dismissed his attempt at humor with irritation. Talk show host Graham Norton also admitted De Niro was one of his worst guests ever, saying the actor was inarticulate and unengaging. Despite his iconic roles, De Niro’s off-screen demeanor has often been described as cold.
12. Kiefer Sutherland
Freddie Prinze Jr. had such a negative experience working with Kiefer Sutherland on 24 that he nearly quit acting altogether. Prinze described Sutherland as unprofessional, difficult, and dismissive on set, making the environment unbearable. He even compared working at WWE with Vince McMahon as less stressful than working alongside Sutherland. For Prinze, the experience highlighted how toxic behavior from a costar can sour an entire career opportunity.
13. Christina Aguilera
Valerie Bertinelli once shared her disappointing encounter with Christina Aguilera at a Van Halen concert. After complimenting the pop star, Bertinelli said Aguilera completely ignored her and gave her a cold look. Considering Aguilera’s reputation for diva-like behavior in the industry, the moment didn’t come as a shock to some. Still, for Bertinelli, who approached with genuine kindness, it was a memorable brush-off from one of music’s biggest names.
14. Hugh Grant
Jon Stewart labeled Hugh Grant as the “worst guest” he ever had on The Daily Show. Stewart claimed Grant was dismissive, constantly complained about the promotional clip shown, and treated the staff poorly. The incident was so bad that Stewart vowed never to have him back. Later, Grant admitted he had been rude and publicly apologized, blaming his “inner crab.” Still, the damage to his reputation as a guest was already done.
15. Gary Lightbody
Comedian Em Rusciano revealed that Snow Patrol frontman Gary Lightbody was the rudest celebrity she ever met. During an interview, he reportedly flipped her off for the entire duration after she asked about the band’s hit song Chasing Cars. According to Rusciano, Lightbody seemed annoyed and dismissive, making the situation uncomfortable. The behavior was shocking considering the song had brought the band massive success and global recognition.