It's always awesome to see celebrity siblings supporting one another for their latest movie roles or award wins, but some of these A-list siblings look so different, fans would think they were just close friends or even each other's significant other!

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We often compare a Hollywood star to their famous parents or even grandparents, but we never take a look at some of the celebs that look very different than their just as famous brother or sister. Actress Blake Lively looks nothing like her older sister Robyn Lively, but both stars are just as stunning as the other. And then there's Eric and Julia Roberts, who are both talented actors and who fans probably had no idea were brother and sister.

10 Blake & Robyn Lively

Most people don't know that actress Blake Lively has four siblings, brothers Jason and Eric, and sisters, Lori and Robyn. The actress is the youngest in her family and she has a rather large age gap between her two sisters. While there are some similarities between her and her two older sisters who are over 15 years older than Blake, most fans would not know that they are actually siblings.

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Like Blake, older sister Robyn Lively is also an actress and most recognized for her role in the movie Teen Witch. She has also starred in numerous television roles such as Doogie Howser, M.D., Twin Peaks, and Saving Grace. 

9 Rooney & Kate Mara

Kate and Rooney Mara are both big-named movie stars but few people know that they are actually sisters. Kate is known for her roles in the movies Fantastic Four, A Teacher, and the Netflix show House of Cards, while younger sister Rooney has starred in The Girl With the Dragon Tattoo and has worked alongside her husband actor Joaquin Phoenix in Her.

What most people don't know is that these two sisters' family business is actually football. Their great-grandfather was Timothy James Mara, who founded the New York Giants.

8 Kim & Khloe Kardashian

Everyone knows the famous reality star siblings, Kim, Kourtney, Khloe, and Rob Kardashian, but there has always been speculation if sister Khloe has the same father as her older siblings. While Kim, Kourtney, and Rob all have Armenian features thanks to their father, the late Rob Kardashian, Khloe was born with blonde hair and fair skin.

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Of course, there was that huge rumor that Khloe was the daughter of O.J. Simpson or Kris Jenner's hairstylist, but that turned out to be all lies.

7 Eric & Julia Roberts

Did anyone know that Eric and Julia Roberts were siblings? Eric Roberts is the actress's older brother and has been in countless movies and television shows since the 1980s. He is also the father of actress Emma Roberts.

Eric Roberts has previously expressed how much his daughter looks like Julia, telling Us Weekly, "They look so much alike that I love pictures of them when they're side-by-side," adding, "They're both such Robertses. You know? It's really cool to look at them. I love seeing them together."

6 Aimee & Kelly Osbourne

Fans who have watched the Osbournes grow up on their reality television series back in 2002-2005 remember siblings Kelly and Jack Osbourne, but might not know that they have a middle sister named Aimee.

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According to CNN, Aimee Osbourne did not want to be on the famous rockstar family show because she valued what little privacy she had. "I always really valued my privacy within my family. And for me personally, and for who I am, you know, as far as morally and also just to give myself a chance to actually develop into a human being as opposed to just being remembered for being a teenager, it didn't really line up with what I saw my future as," she revealed.

5 Kate & Oliver Hudson

Kate and Oliver Hudson are both very attractive Hollywood stars and they got their good looks thanks to having the same parents, actress Goldie Hawn and Bill Hudson. While people may recognize Kate a little more thanks to her roles in movies like How To Lose a Guy in 10 Days and Almost Famous, her older brother is also an accomplished actor.

Oliver Hudson is best known for starring in Walk of Shame, Executive Decision, and the horror movie Black Christmas. siblings The famous siblings have a close relationship with one another, with Kate telling Health magazine this year, "the healthier your relationships are with your family, the healthier your relationship will be with yourself."

4 Jared & Shannon Leto

Jared and Shannon Leto are indeed brothers and are both very talented musicians with Jared the lead vocalist and Shannon the drummer of their rock band 30 Seconds to Mars. The brothers are extremely close and are often seen walking red carpets together like the 2014 Oscars, where the famous brothers took their mom, Constance.

Jared Leto ended up winning Best Supporting Actor at the 2014 Oscars for his role in Dallas Buyers Club and had his brother and mother there cheering him on.

3 Zooey & Emily Deschanel

These famous brunettes are actually sisters and have both found extreme success in Hollywood. Zooey Deschanel is most known for her role on the television show New Girl, while older sister Emily is famous for her role on Bones. 

In an interview for BuddyTV, Emily shared that while they are both well-known actresses, she would have chosen a different career path. "I think we both loved doing plays since we were really young. But I didn't think of it as doing it as a profession. I think Zooey knew she wanted to be an actress from when she was very young. Whereas I didn't think I wanted to do that.," adding that she wanted to be an architect when she was growing up.

2 Ryan & Mandi Gosling

Mandi Gosling is famously known as actor Ryan Gosling's sister and she is the sister-in-law of Eva Mendes. While Mandi has not taken the same career path as her famous brother, she has often been seen side-by-side with the Notebook star while on red carpets and award shows.

According to NaiBuzz, Mandi works as one of the producers for Dateline on NBC and has been an associate producer for the reality television show Miss Advised. Mandi was also the casting director for Pharell William's song Happy. 

1 Ariana & Frankie Grande

One of the cutest pair of celebrity siblings is Ariana and Frankie Grande. The celebrity siblings think of one another as best friends more than brother and sister, even though they are 10 years apart.

While on the 2019 Nickelodeon Kids' Choice Awards red carpet, Frankie gushed about his younger sister, sharing how close they really are. "We're talking 24/7. I was talking to her on my way in and I'll probably talk to her as soon as I pick my phone back up. You know, we're very, very close."

NEXT: 10 Photos Of Celebs With Their Lookalike Sisters