Rainer Ptacek, also known mononymously as Rainer (June 7, 1951 – November 12, 1997), was a Tucson, Arizona-based American guitarist and singer-songwriter.
His guitar technique, which incorporated slide, finger-picking, tape loops and electronic manipulation, earned him admiration of some notable musicians such as Robert Plant and Billy Gibbons.
A tribute album to Ptacek, The Inner Flame, included contributions by Plant, Jimmy Page, PJ Harvey, Emmylou Harris and others, and was indicative of his reputation as a "musician's musician".
He was diagnosed with a brain tumor in early 1996 and died nearly two years later, after the illness recurred.