Being a talented girl she began her career at age 11 by working in some commercials and as a print model for various catalogs, magazines and Disney products. As a child actress she also was a guest star on primetime shows such as “Without A Trace”, “House M.D.”, and “CSI”. In the 2008 she played Deb Rogers in the small-budget movie “Cop Dog”. At the same year she appeared in movie “Our First Christmas” playing role of Tory. She also takes a part in few episodes of Hawthorne TV series in the 2009.

Cassi Thomson also worked in the music industry as singer and songwriter since 2008. Along with producer Andrew Lane she worked on her debut album. Her first music video appeared in 2008, featuring her single "Caught Up In You", where also was an actor Taylor Lautner. Her first album, titled “Cassi Thomson” was released in the 2015, six songs from this album are now produced and available on iTunes .

In addition to her musician career, Thomson also continuing television work. She has appeared in a number of television movies and independent films during 2011-2012 like a “Rock the House” and “Teenage Bank Heist”. She played minor role of Nikki Papagus in the ABC Family Award Winning series “Switched at Birth” from 2012 till 2014, but this role was a recurring. During 2009-2011 she appeared in HBO TV series “Big Love” along with Bill Paxton, playing character Cara Lynn.

Cassi was 15 when she joined the cast of this project and appeared in the end of third season, soon she became a series regular actor in Season 4, staying with the show till the end. In the 2011 she played secondary role of Cara Lynn in one of episode of “Margene's Blog”. Cassi also won the female lead role in the theatre release movie "Left Behind" in the 2014, playing along with Nicholas Cage and Chad Michael Murray. This movie was released in October the same year and was full of negative critics and didn't bring to her popularity. Cassi appeared in the movie “Grave Halloween” as Amber in 2013. Next year she played Ally in “1000 to 1: The Cory Weissman Story” and Chloe Steele in “Left Behind”. In the 2016 Cassi Thomson played Addison Wells in the new TV series “Hawaii Five-0” and appeared as Annette in thriller movie “Storage Locker 181”.

Cassi don’t like to show her personal life matters like her love affairs or any romantic relationship. Currently she is not married. She is five feet and three inch tall. There is no information about her net worth.