Post-metal/atmospheric sludge/post-rock/experimental band founded in 2000 in Kokkola, Finland as Pulse (with Juho Niemelä, Markus Myllykangas and Johannes Nygård); in 2001 Ariel Björklund joined, and the band changed name to Callisto. Later relocated to Turku/Helsinki.

Current lineup:
Juho Niemelä – bass (2001–present), backing vocals (2001–2006)
Ariel Björklund – drums (2001–present), percussion (2005–2013)
Markus Myllykangas – guitars (2001–present), vocals (2001–2008), backing vocals (2008–present)
Jani Ala-Hukkala – vocals (2008–present)
Jani Rättyä – percussion (2013-present), throat singing (2014–present)
Tero Holopainen – guitars (2013–present)
Janne Storm – keyboards, samples, additional instruments (2015–present)

Former members:
Johannes Nygård – guitars (2001–2013, guest in 2019)
Henri Kuittinen – guitars, keyboards, electronics, samples (2005)
Arto Karvonen – keyboards, samples (2005–2015)

Touring musicians:
Miika Luoma – drums (2015–present)

Former touring musicians:
Esa Klapuri – saxophone (2011)
Jonas Olsson – vocals, guitars (2011)
Kim Mäenpää – female vocals (2011)
Seba (Kepsah) – saxophone (2015)