John Knowles (born 1942) is an American acoustic guitarist, one of six Certified Guitar Players (the other five being Tommy Emmanuel, Marcel Dadi, Chet Atkins, Steve Wariner, and Jerry Reed), a lighthearted title given out by Atkins to collaborators whom he considered exemplary finger-style guitarists.
There are four CGP awardees whose titles were formalized by the CAAS (Chet Atkins Appreciation Society) fan club. The others three, besides Dr. Knowles, being Tommy Emmanuel, Steve Wariner, and Jerry Reed. After Chet Atkins' death, Chet's daughter gave a posthumous CGP to Paul Yandell, Chet's long time guitar partner. She said that the idea came from her deceased father in a dream, and that it would be the final CGP award.
Knowles first learned music through the accordion. Later, he picked up the ukulele and started transposing from the accordion's keyboard to the fretboard. The musical skills he developed at a young age allowed him to learn guitar in high school. Discovering that the guitar was not well respected in the music community, Knowles worked for and received a Ph.D. in physics from Texas Christian University while playing guitar on the side.