Casey Lee Williams is the daughter of Jeff Williams and Sandy Lee Casey. She is the primary vocalist for the RWBY soundtrack. She is also the vocalist for Weiss Schnee's singing in the "White" Trailer and "Tipping Point".

Prior to her work on RWBY, she also performed songs for Red vs. Blue, another Rooster Teeth series, in Seasons 9 and 10.

At RTX 2014, Casey cosplayed as Ruby Rose and performed a short acoustic set along with her father and other musicians at the RWBY Music Panel. At RTX 2015, Casey cosplayed as Weiss for the live music concert, once again performing alongside her father, as well as Video Game Orchestra and the band, Barenaked Ladies. She again performed live during RTX 2016 at Austin City Limits Live with Jeff Williams' Freelance Orchestra.