[2] McIntosh attended Firbank and then Melbourne Girls Grammar School, where she recalled "I involved myself in every play and every musical and I did drama classes.
[6] In March 2003, McIntosh signed a three-year contract to appear in the Australian soap opera Neighbours.
[8] McIntosh's music career began in 2004 when her version of the song "Santa Claus Is Coming to Town" was included on the album The Spirit of Christmas 2004.
[10] At her appearance on Habbo Hotel on 8 March 2007 McIntosh confirmed that the re-packaged edition will feature remixes of the singles released from Tightrope as well as the bonus track "Catching My Breath".
McIntosh was also nominated for "Spankin' New Artist" at the 2006 MTV Australia Video Music Awards, at which she also performed "So Do I Say Sorry First?"
McIntosh performed at university bars and nightclubs across the UK from September to November 2007 to build her popularity there.
In May 2008, the Herald Sun reported that McIntosh had been in Los Angeles, meeting with potential agents and managers.
She auditioned for roles in Transformers: Revenge of the Fallen (2009), the CBS mini-series Harper's Island, and Beverly Hills, 90210, but failed to secure them.
[13][14][15] McIntosh appeared in the thriller Liars All (2013) as Casey Kass,[16] and in Red Herring (2014) as Charlie, which co-starred former Neighbours castmate Holly Valance.
[17] McIntosh reprised the role of Sky Mangel in Neighbours for one episode in 2015, as part of the show's 30th-anniversary celebrations.
[7] After a five-year acting career hiatus, McIntosh reprised her role on Neighbours as Sky Mangel on a recurring basis in 2020.