Lester William Polsfuss (June 9, 1915 – August 13, 2009)—known as Les Paul—was an American jazz, country and blues guitarist, songwriter andinventor. He was the inventor of the solid-body electric guitar which made the sound of rock and roll possible. He is credited with many recording innovations. Although he was not the first to use the technique, his early experiments with overdubbing (also known as sound on sound), delay effects such as tape delay,phasing effects and multitrack recording were among the first to attract widespread attention.

His innovative talents extended into his playing style, including licks, trills, chording sequences, fretting techniques and timing, which set him apart from his contemporaries and inspired many guitarists of the present day. He recorded with his wife Mary Ford in the 1950s, and they sold millions of records.

Among his many honors, Paul is one of a handful of artists with a permanent, stand-alone exhibit in the Rock and Roll Hall of Fame. He is prominently named by the music museum on its website as an "architect" and a "key inductee" along with Sam Phillips and Alan Freed.

Paul's innovative guitar, "The Log", built after-hours in the Epiphone guitar factory in 1940, a 4" × 4" chunk of pine with strings and a pickup, was one of the first solid-body electric guitars. Paul Tutmarc of Audiovox Manufacturing Co. built a solid body electric bass in 1935 and Adolph Rickenbacker had marketed a solid-body guitar in the 1930s and Paul A. Bigsby had built one for Merle Travis in 1948 and Leo Fender also independently created his own (the Fender "Broadcaster" later changed to "Esquire" for copyright reasons, a single pickup model) in 1948. Although Paul approached the Gibson Guitar Corporation with his idea of a solid body electric guitar, they showed no interest until Fender began marketing its Esquire which later had a second pick-up added and became known as the Telecaster.

The arrangement persisted until 1961, when declining sales prompted Gibson to change the design without Paul's knowledge, creating a much thinner, lighter and more aggressive-looking instrument with two cutaway "horns" instead of one. Paul said he first saw the "new" Gibson Les Paul in a music-store window, and disliked it. Although his contract required him to pose with the guitar, he said it was not "his" instrument and asked Gibson to remove his name from the headstock. Others claimed that Paul ended his endorsement contract with Gibson during his divorce to avoid having his wife get his endorsement money. Gibson renamed the guitar "Gibson SG", which stands for "Solid Guitar", and it also became one of the company's best sellers.

The original Gibson Les Paul-guitar design regained popularity when Eric Clapton began playing the instrument a few years later, although he also played an SG and an ES-335. Paul resumed his relationship with Gibson and endorsed the original Gibson Les Paul guitar from that point onwards. His personal Gibson Les Pauls were much modified by him—Paul always used his own self-wound pickups and customized methods of switching between pickups on his guitars. To this day, various models of Gibson Les Paul guitars are used all over the world by both novice and professional guitarists. A less-expensive version of the Gibson Les Paul guitar is also manufactured for Gibson's lower-priced Epiphone brand.

On January 30, 1962, the US Patent and Trademark Office issued Paul a patent, Patent No. 3,018,680, for an "Electrical Music Instrument."