Cassie Steele's mother is of Filipino descent, while her father is British-Canadian. Steele appeared in the 2007 MTV movie, Super Sweet 16: The Movie. Steele is currently living in Los Angeles in order to concentrate on her music career. She is a former member of the band KaraMel. She attended London School of Dance in Scarborough, Ontario and trained in ballet and jazz.
Steele began crafting her own made-up songs to go with her poetry when she was in first grade, then began taking singing lessons. She has been a regular cast member on Degrassi: The Next Generation, playing the character of Manny Santos since the age of eleven. At the age of thirteen, Cassie wrote and recorded the song “Prayer,” which was used nationally to promote HIV/AIDS awareness. She has been on My Babysitter's a Vampire as the girl in the Twilight parody movie.
Steele is close friends with her costars Miriam McDonald, Shenae Grimes, and Nina Dobrev. She also is close friends with Sara Paxton. She is the older sister of Alex Steele, who played Angela Jeremiah, Joey Jeremiah's daughter and Craig Manning's half-sister, and Class of 2016 member, Tori Santamaria.
- How Much for Happy (2005)
- Destructo Doll (2009)
- Shifty EP (2012)
- Patterns EP (2014)
- Cassie is a Sagittarius.
- Cassie Steele and Alex Steele are two of ten actors on Degrassi to be related. The others were Christopher Charlesworth (Scooter Webster) and Sarah Charlesworth (Susie Rivera), Anais Granofsky (Lucy Fernandez) and Lea-Helen Weir (Norah-Jean Rivera), Duncan Waugh (Arthur Kobalewscuy) and Annabelle Waugh (Dorothy), and Angela Deiseach (Erica Farrell) and Maureen Deiseach (Heather Farrell).
- It was revealed in an interview that Steele's favorite Degrassi character is Holly J. Sinclair.
- Cassie stated in interview that she could be friends with her character Manny Santos.
- Her Youtube channel .
- Degrassi co-star and close friend, Shenae Grimes, directed the music video for her new single "Mad."
- Cassie Steele starred alongside Daniel Kelly as Valerie Vont in the Lifetime movie Sorority Surrogate in 2014.
- She was the youngest member of the original cast of Degrassi: The Next Generation and the youngest regular to join the cast at the age of 11.
- She was the first actor to be younger than their character. The second was Dante Scott. Although Cassie was four months younger than Manny, Dante is two years younger than Vijay.
- Her mother Lily Steele emigrated from the Philippines to Canada in 1982 with her parents and seven siblings.
- Our Lips Are Sealed (1) is the final episode in which she and her sister Alex both appear.
- She originally had the role of Gabriella in the movie High School Musical, but because of schedule problems filming had to leave the project.