Katherine Lynne Bjelland (born December 9, 1963) is an American musician. She rose to prominence as the lead singer, guitarist, and songwriter of the alternative rock band Babes in Toyland, which she formed in Minneapolis, Minnesota, in 1987. She has been noted for her unusual vocal style alternately consisting of shrill screams, whispering, and speaking in tongues, as well as for her guitar playing style, which incorporates "jagged" tones with "psychotic rockabilly rhythms".Born in Salem, Oregon, Bjelland was raised in nearby Woodburn, and learned to play guitar as a teenager from her uncle, with whom she performed in his band shortly after graduating high school. Upon dropping out of the University of Oregon at age nineteen, Bjelland relocated to Portland, where she became involved in the city's punk rock scene. There, she became friends with Courtney Love, and formed the band Pagan Babies.

After the dissolution of Pagan Babies in 1985, Bjelland relocated to Minneapolis, where she formed Babes in Toyland with drummer Lori Barbero. The band's debut record, Spanking Machine, was released in 1990, after which they toured Europe with Sonic Youth. This was followed by their second album, Fontanelle (1992). The band would release their third studio album, Nemesisters, in 1995. In the mid-late 1990s, Bjelland collaborated on other musical projects, including contributing as a bassist in the band Crunt with her then-husband, Australian musician Stuart Gray.

Babes in Toyland formally disbanded in 2001, and Bjelland began working with Katastrophy Wife, a project under which she released the albums Amusia (2001) and All Kneel (2004). She remained out of the public light for several years before publicly revealing in 2007 that she had been diagnosed with schizoaffective disorder. In 2015, she reunited with Babes in Toyland and began touring internationally for the first time in over a decade. Bjelland later retired in 2017.