Nicole de Boer began her acting career as a child in her hometown Toronto, Ontario, Canada. A shy child, she one day came home and, to the astonishment of her family, told them she had gotten the lead in the play "The Wizard of Oz". With the blessing of her parents, her grandmother helped her to find an agent and shortly afterward, she made her television debut in a Christmas Special starring Red Skelton and Vincent Price. Throughout her childhood, Nicole was active in commercials and theatre.

At age seventeen, she was cast as a series regular in the CBC drama 9B (1988). Nicole's numerous television credits include: Beyond Reality (1991), First Resort, Catwalk (1992), The Kids in the Hall (1988), The Outer Limits (1995), PSI Factor: Chronicles of the Paranormal (1996), Maniac Mansion (1990) and Mission Genesis (1997). On film, she was featured in Kids in the Hall: Brain Candy (1996), co-starred in National Lampoon's National Lampoon's Senior Trip (1995) with Matt Frewer and Tommy Chong and was in the critically received sci-fi horror film Cube (1997). While filming the series Dooley Gardens (1999) in Newfoundland, she got the call and was cast in the seventh and final season of Star Trek: Deep Space Nine (1993), replacing Terry Farrell as the symbiont host Ezri Dax.