Per Jonas Wiberg (born 8 June 1968) is the former keyboardist of Swedish progressive death metal band Opeth, and a member of Michael Amott's stoner metal band Spiritual Beggars.
Wiberg was born in Borlänge. He toured with Opeth from the 2003 Deliverance/Damnation tour onward, and joined Opeth officially in 2005. Wiberg provided backing vocals for Opeth in addition to his keyboard duties. Before joining Spiritual Beggars he was a member of Death Organ, a band based in Borlänge. He has also fronted the band Boom Club, of the same area.
Wiberg played the keyboard in the intro to "Enemy Within" by the melodic death metal band Arch Enemy. He has also played piano on Swedish progressive rock band Anekdoten's 1993 release Vemod. In 2007, he collaborated on a project called King Hobo with Clutch drummer Jean-Paul Gaster and Kamchatka guitarist Thomas Andersson.
It was announced on 6 April 2011 that Wiberg was leaving Opeth as part of a mutual decision between him and the other band members. Since 2012 he has been a live musician for the Swedish doom metal band Candlemass as well as joining Swedish band Switchblade on selected dates as a keyboard player. In 2013 he joined Swedish trio Kamchatka as a bass player and full-time member. He plays on the Kamchatka albums The Search Goes On and Long Road Made of Gold.