The star, 39, has channelled her inner cheerleader for a new film, sporting straight blonde bangs and a heavy face of makeup.
Sharing multiple film stills from Instagram, the mother-of-two revealed how difficult her new role was.
“I’m not sure how to put into words what this last month has meant to me,” she began. “A month ago, I was given an opportunity to push myself beyond my comfort zone and accept a film that made me uncomfortable.
“It was uncomfortable because I knew if I took on this role there was no holding back. It was going to cost me. I would have to dive into some dark places that I safely put in a box and open up some wounds that were almost healed. But I had to do it.”
Tammin looks unrecognisable as the energetic cheerleader, sporting a giant blue and white bow in her high ponytail and clutching a pair of cheerleader pom poms.
The Australian actress explained that she took the role for her daughters, to show them what she was ‘capable’ of achieving.
“I had to show them their mama could learn CHEER (say what?!) and perform on stage with professional dancers 15 years younger than her. I had to show them that anything is possible. If you just colour outside the lines,” she wrote.
Tammin has often played characters that are much younger than her, taking on the role of 17-year-old Jenna Marshall in Pretty Little Liars when she was 27.
At this stage, the star hasn’t shared the name of the film or where it will be released, but she did say that it will be on ‘a streamer’.
Her celebrity friends gushed over the Instagram post, saying she looked ‘amazing’ and that they were excited to see her new project.
“Wowwww!! I’m so friggin’ proud of you! And not to be vapid but — you are just gorgeous!” wrote TV host Dawn McCoy.
“I am screaminggggggg! When does this come out?! So proud of you!” influencer Clarissa Luna added.
“Can’t wait to see it!” Bachelorette star Ali Manno chimed in.
Fans told Tammin the new look 'suits her', and many applauded her for trying something new.
"Sometimes it's so important to get out of our comfort zones. Scary as hell but important," one person wrote.
"Living for these pics! I'm so proud of you! I've watched your journey from Home and Away and I'm just so proud of you gal!" another wrote.
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