Pasi Koskinen (born January 1972) is a Finnish metal vocalist and musician, currently the vocalist and guitarist of the band Datura Nemesis (2013–), but he is perhaps best known as the vocalist of the band Amorphis (1995–2004).
Koskinen was also the vocalist of the bands St. Mucus, (a band he created under that name and also was the guitarist) from 1992 to 1994, Ajattara (under the alias I. Ruoja Suruntuoja and was also the guitarist plus did some keyboards) from 1998 to 2012, Shape of Despair from 2001 to 2010, To Separate the Flesh from the Bones (under the alias Herr Arschstein and was also the guitarist) from 2004 to 2006 & Mannhai from 2005 to 2009.
Koskinen did co-vocal production on Zero Nexus by Shade Empire, guest vocals on the songs "Vapahtaja" on the album Vuoroveri by Saattue and "Asmodee" on the album Womb of Lilithu by Necrophobic.