Thinking Plague is an American avant-garde progressive rock group founded in 1982 by guitarist/composer Mike Johnson and bass guitarist/drummer Bob Drake. Based in Denver, Colorado, the band has been active off and on since 1982, taking on a number of musicians over the years. They have made seven studio albums between 1984 and 2017, and released one live album recorded at NEARfest in 2000.

Their music is a mix of rock, folk, jazz and 20th-century classical music. Music.com remarked that "...Thinking Plague stand out as a shining example of avant-garde music blended with just enough rock for it to be called progressive rock..."

While never directly related to Rock in Opposition (RIO), Thinking Plague was strongly influenced by this late-1970s movement, particularly Henry Cow and Art Bears. In spite of Johnson's dislike of the term, the band has often been categorized as a "RIO" band.