Psychotic Waltz is a legendary American progressive metal band formed in San Diego, California, in 1986. They stood out in the early 90s progressive metal scene by blending aggressive, complex time signatures with psychedelic atmospheres and unique, Jethro Tull-inspired flute instrumentation played by frontman Buddy Lackey (Devon Graves).

Their early masterpieces, A Social Grace (1990) and Into the Everflow (1992), established them as underground icons, particularly in Europe. Mid-career releases such as Mosquito (1994) and Bleeding (1996) saw the band shift toward a more groove-oriented, grunge, and alternative metal sound, showcasing their stylistic versatility. Following a break-up in the late 1990s, the original lineup reunited in 2010 and returned with their critically acclaimed comeback album The God-Shaped Void in 2020.