Nicola Stephenson (born 5 July 1971) is an English actress. She is known for her roles as Margaret Clemence in the Channel 4 soap opera, "Brookside", from 1990 to 1994; Julie Fitzjohn in the BBC One medical drama series, "Holby City", from 1999 to 2001; Sarah Williams in the BBC One drama series, "The Chase", from 2006 to 2007; Allie Westbrook in the BBC one school-based drama series, "Waterloo Road", during 2014; and Tess Harris in the long-running ITV soap opera, "Emmerdale", from 2015 to 2016.