The Rookie cast before they were famous: see epic throwback photos of Nathan Fillion, Eric Winter & more

Nathan Fillion grew up in the city of Edmonton in Alberta, Canada. Extremely close to both of his parents, the TV star has also spoken of his endless admiration for his older brother, Jeff. Pictured with his sibling above, it's pretty easy to spot Nathan, although he's sporting a shorter haircut these days! 

Nathan knew he wanted to be an actor from a young age, but with limited options in Edmonton, the fledgling star took a practical approach and decided to become a teacher. While he may have studied for a degree at the University of Alberta, the 53-year-old ultimately decided to pursue a career in acting, heading to New York where he landed his earliest TV roles. And we're so glad he did – it wouldn't be The Rookie without John Nolan. 

Eric Winter was born in La Mirada, California, and while little is known about his childhood, the 47-year-old has given fans a glimpse of his favourite trends from way back when. 

"This is what happens when you go through old pics... probably took me 45 mins to blow dry my hair that perfectly," he joked on Instagram. "And just the right amount of aqua net, learned it from the man himself...miss ya dad #fbf."

Fun fact about Eric, like Nathan he started with a different career path in mind and studied to become a doctor. "I was actually a psycho-biology major and I wanted to be a doctor," he told DA MAN in 2019. "While taking some drama classes as an elective, I started falling in love with the creative arts."

Imagine how different things would be if he hadn't discovered his passion for acting! 

How adorable is this throwback photo of Melissa O'Neil with her mom and baby brother?! In the caption, the star explains that she was eight at the time and that it was taken on the Hong Kong ferry. 

A performer from day one, Melissa was raised in Calgary and appeared in several musicals and plays during her high school days. At just 17, she won 2005's Canadian Idol, becoming the first female winner, the first winner of Chinese descent and the youngest winner in the show's history – an impressive feat.

After releasing several albums and heading to Broadway, Melissa committed her full attention to acting in 2015, bagging roles in Dark Matter (2015-17), This Life (2015), Rogue (2016) and iZombie (2018) before joining The Rookie in 2018. 

Born in Hartford, Connecticut, Jenna Dewan had lived in seven different cities by the time she was seven. While attending Notre Dame Preparatory School in Towson, Maryland, she became a Varsity cheerleader – a passion she continued when she transferred to  Grapevine High School in Grapevine, Texas. In her senior year, Jenna was also voted prom queen. 

For Jenna, dancing was her first foray into the creative arts, and she appeared as a backing dancer for artists including Missy Elliott, Janet Jackson, and Christina Aguilera during the early days of her career. 

After bagging minor roles in film and TV shows, Jenna got her big break when she was cast as Nora Clark in the hit dance film, Step Up (2006), and the rest, as they say, is history!

Mekia Cox recalled how she got started in showbiz. Chatting to Tell Tale TV, she said: "I started dancing first when I was about two and a half years old, and I moved into singing kind of in elementary school then middle school. 

"And it was probably in the beginning of middle school that I really got into acting. I was born in The Virgin Islands and we moved up to Orlando. And, you know, there's Disney World and Nickelodeon there, and I started to do some work on shows both at Disney and at Nickelodeon in Orlando. That was kind of how I got my foot in the door initially." 

Back in 2013, Mekia posted a sweet throwback photo from her childhood on the Virgin Islands, noting that she misses her life there. Nowadays, however, the actress is based in Los Angeles where The Rookie is filmed, and shares two children with her husband, Britt Leach.