Celebrity website TMZ.com, citing first responder radio communications, said Weiland died from cardiac arrest while asleep on his tour bus.
Bloomington police said the death was being investigated by the Hennepin County Medical Examiner's Office. The Medical Examiner's office gave no cause of death in a brief statement on Friday.
The California-born singer, who had acknowledged a long history of cocaine and heroin abuse, was kicked out of Stone Temple Pilots in 2013 for what his bandmates' lawyer called "destructive behaviour". He also performed with the group, Velvet Revolver, for several years.
Weiland, known for his growling vocals and shock of dyed red hair, came to symbolise the early 1990s grunge era as lead singer and lyricist for the Stone Temple Pilots. Adept at altering his vocal style, he sometimes sang through a megaphone.
Scott Weiland was one of the top 5 trending items on Twitter on Friday.
Weiland co-founded Stone Temple Pilots, also known as STP, in the late 1980s, which went on to score such guitar-heavy hits as Plush in 1993 and Interstate Love Song the following year.
The band broke up in 2003 but reunited five years later only to collapse in acrimony again in February 2013 when bandmates Dean DeLeo, Robert DeLeo and Eric Kretz forced Weiland out.
Weiland is survived by two children with his ex-wife, Mary Forsberg, who wrote in her 2009 memoir Fall to Pieces that there was a time when the couple, while beset by drug addiction, took a limousine together to rehab.
The debut album of Weiland and The Wildabouts, Blaster, was released this year.
-AAP