PH formerly known as Mr. Peter Hayden is a Finnish alternative metal band often filed under post-metal, spacerock or psychedelic doom.
Group was formed in Kankaanpää, Finland in 2000. On their fourth album, Eternal Hayden, group begun to refer to themselves just by their logo, the PH-monogram, leading to confusion what the band should be called. Since then all variations from Mr. Peter Hayden to PH have been used. Group is also part of the Wastement collective.