Guadagni's first role after graduation was playing
Miranda, with
Paul Scofield as
Prospero, in a production of
The Tempest in the
West End of London. Her theatre work in Canada includes ''
A Midsummer Night's Dream at Stratford Third Stage; Zastrozzi
and Criminal Genius
at the Factory Theatre; Hamlet and Mother Courage for the National Arts Centre; The Seagull and The Member of the Wedding at Tarragon Theatre; and OD on Paradise'' at
Theatre Passe Muraille. Guadagni has been nominated for five
Gemini Awards for her work on television, and received the award in 1998 (Best Supporting Actress,
Major Crime) and 2004 (Best Actress in a Guest Role,
Blue Murder, "Eyewitness"). She was a mainstay of the repertory cast of the A&E Network's
A Nero Wolfe Mystery (2001–2002), playing no fewer than 13 highly varied roles in the course of the TV series and the pilot,
The Golden Spiders: A Nero Wolfe Mystery (2000). She also played a leading role in cult sci-fi film
Cube in 1997. In 2002 Guadagni made her playwriting debut with
In the Wings, adapted from the 1998 novel by
Carole Corbeil, which she performed at Toronto's Theatre Passe Muraille. In 2011 an abbreviated version of her seven-character, one-person show
Hooked, written by
Carolyn Smart, was part of Toronto's Summerworks Theatre Festival schedule, with performances at Theatre Passe Muraille Backspace. Guadagni taught voice and scene study for five years at
George Brown College as well as at the University College Drama Program in
Toronto,
Ontario, and has also worked at the
National Theatre School of Canada in Montreal. She has provided coaching and dramatic training for clients of the firm The Humphrey Group since 1995. In 2019, she played the demented matriarch Helene Le Domas in the horror film
Ready or Not. ==Awards==