After a lead role in Pirate Islands, she starred as Rosie Cartwright in The Sleepover Club in 2003. She transitioned to mature audience programs with a guest role on Blue Heelers in 2003.
Taylor travelled to the United Kingdom in late November 2007, and on 1 December 2007 she turned on the Weymouth Christmas Lights. On 19 December, Taylor starred as Snow White in a Christmas pantomime, again in Weymouth. In 2009, she was in an episode of All Saints and filmed a short drama/comedy movie called The Laundromat. Taylor filmed a role in the horror movie 6plots. She later filmed the pilot of Winners & Losers.
Taylor, as many Australian actors, got her big breakthrough in the Australian soap opera Neighbours in 2005. She secured the role of Janae Timmins after previously appearing in a guest role in 2003. Taylor had originally auditioned for the role of Lana Crawford, however, it was Actress Bridget Neval who was eventually cast. In 2007, Nell Feeney and Sianoa Smit-McPhee, who play Taylor's on-screen mother Janelle Timmins and sister Bree Timmins, were written out by executive Producer Ric Pellizzeri, but it was confirmed that they wanted Taylor-Cotter to remain in the serial as Janae. Later that year, Taylor-Cotter decided to quit the serial to pursue other projects such as pantomime and a further career in the USA. One of the contributing factors that helped Taylor-Cotter reach this decision was that all of her on-screen family had been written out and new cast members gave the serial the feel of a different place. She also added: "It just didn't feel like the family that I joined when I started three years ago. Taylor-Cotter was one of many cast members that quit the serial at the same time. Taylor-Cotter finished filming her final studio scenes in 2007 and her final episode was screened on 8 February 2008. In 2007, Taylor was nominated for Best Female at the Inside Soap Awards.
On 1 March 2013, it was announced that Taylor was cast as lead character of Clarke in the new CW post-apocalyptic drama series The 100. "I didn't actually audition. I'd been living in LA for about a month and my credit card was stolen and all my money was taken – spent at Home Depot, which was great – and I was ready to pack my bags and go back to Australia because I didn't know how I was going to survive in LA any longer and then I got a call from my manager to say that an audition I'd done months ago for a film had been looked at by the producers of this TV show called The 100 and they wanted me to go in for a reading the next day. So I read the script that night and loved it and went in for the meeting the next day and got the role. Before I knew it I was on a plane to Vancouver to shoot the pilot and my whole life changed." - Taylor explained about how she got the part. The series premiered on Wednesday, 19 March 2014.
In April 2016, it was announced that Taylor will star in the independent police drama Thumper alongside Daniel Webber. Taylor's character is described as an undercover police officer out to bust a drug ring at a local high school by pretending to be a tough new girl. Her character becomes emotionally involved with the underprivileged students that she's investigating.
