Johnson came to prominence in the mid-1990s as part of the original ''Power Rangers'' cast. After leaving the show, she had several parts in made-for-television movies before landing a leading role in ''Felicity'' on The WB, which ran from 1998-2000. In the 2000s, she continued her acting career, with main roles in ''The Division'' and ''Flashpoint'', as well as recurring and guest roles on several other shows.
In addition, she has directed and produced two acclamed short films : ''Bent'' (2013) and ''Lines'' (2014).
Johnson is also a singer-songwriter and has released three albums to date.