After graduating from
Bayview Glen School, she completed her education at the
University of Toronto. She played the role of
Jessica Buchanan on the
ABC soap opera
One Life to Live from February 5, 2003 until the series cancelation in 2012. The character is the daughter of original character
Viki Lord Buchanan (played by
Daytime Emmy Award-winner
Erika Slezak since 1971), and gave Williamson the opportunity to portray Jessica's
alternate personalities "Tess", from 2005 to 2006 and again starting in 2008 and 2011. Williamson had previously auditioned for the role of
Jen Rappaport on
One Life to Live, but was rejected because of her resemblance to actress
Erin Torpey (the two looked nearly identical), who was playing Jessica Buchanan on the show at the time. When Torpey resigned in January 2003, Williamson was remembered by the casting department and offered the role of Jessica. She so closely resembled Torpey that many viewers did not notice the change. In 2009, 2010 and 2011 Williamson was nominated for a
Daytime Emmy Award for
Outstanding Supporting Actress for the role of Jessica. In 2009, Williamson appeared as Brandeis on
Gossip Girl in the episode "The Grandfather: Part II"; she reprised the role in the 2010 episode "The Empire Strikes Jack". In 2012, Williamson joined the cast of
Haven as Dr. Claire Callahan for Season 3, which began airing in September 2012. In 2013, Williamson appeared in flashbacks as Vivian Bowers, the murder victim in the NBC TV series
Deception. On May 26, 2016, it was announced that Williamson would originate the role of Claudette Beaulieu on July 5, 2016, on
General Hospital. ==Personal life==