Casey Lee Williams is a singer who's also the daughter of Jeff Williams and Sandy Lee Casey. Her earliest performance in one of her father's soundtracks was in the song "Bye Nikki Bye" in The Strangerhood, when Casey was just six. A few years later Jeff asked 12 year-old Casey to sing for a demo he was writing for Red vs. Blue, and liked it so much he decided to use Casey instead of "hiring some sick soprano opera singer". Casey did two more songs for that show, and then became the primary vocalist for the RWBY soundtrack. In Volume 6, she has a few composer credits for "small ques"[?], which she clarified as being for the music on Salem's backstory.
At RTX 2012, Casey appeared in her father's concert singing Caboose's song "Your Best Friend". She returned two years later, cosplaying as Ruby Rose and performing a short acoustic set along with her father and other musicians at the RWBY Music Panel. At RTX 2015, Casey cosplayed as Weiss Schnee 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 (she couldn't perform in 2017 due to being in Europe at the time of the convention), and returned with them in 2018.
Casey's currently attending the Berklee College of Music, and has formed her own band, OK Goodnight.