Tina Michelle O'Brien (born 7 August 1983 in Rusholme, Manchester, England) is an English actress. She is best known for her role as Sarah Platt in the long-running ITV soap opera, "Coronation Street", from 1999 to 2008 and 2015 onwards, and for her role as Bex Fisher in the BBC school-based drama series, "Waterloo Road", from 2010 to 2011.