Dr. Gregory Walter Graffin (born November 6, 1964 in Racine, Wisconsin), better known as Greg Graffin, is the vocalist and co-founder of the punk rock band Bad Religion. He attended El Camino Real High School.

In 1980, at age 15, Graffin and a few high school classmates formed Bad Religion in Southern California's San Fernando Valley. After making a name for themselves in the Los Angeles punk scene, releasing three EPs and two full-length albums, they disbanded in 1984. However, the band re-formed in 1987, with the How Could Hell Be Any Worse? line-up with an addition of former Circle Jerks guitarist Greg Hetson, and released their highly acclaimed comeback album, Suffer, in the following year. The album was a comeback for Bad Religion as well as a watershed for the Southern California punk sound popularized by their label Epitaph Records, which is owned by guitarist Brett Gurewitz. The band has recorded and toured frequently ever since the release of "Suffer." Bad Religion is known for its articulate and often politically charged lyrics as well as its musically sophisticated (yet fast-paced) harmony, melody and counterpoint.

Graffin and Gurewitz are the band's two main songwriters, though Graffin wrote the bulk of the material on his own for a three-album period in the late 1990's when Gurewitz left the band. Graffin recorded a solo album in 1997, called American Lesion, which consisted of softer, more pop-oriented songs. After a stint with major label Atlantic Records ended in the early 2000s, Bad Religion re-signed with Epitaph and Gurewitz rejoined to record two more albums, and the band released their fourteenth studio album, "New Maps of Hell" in 2007.

In June of 2005, it was reported that Graffin would continue his solo work with the release of Cold as the Clay[1]. The new album is an amalgamation of new songs by Graffin and 18th and 19th century American folk songs. It was produced by Brett Gurewitz and released on Anti- Records on July 10, 2006.

Graffin double majored in anthropology and geology as an undergraduate at the University of California, Los Angeles. He went on to earn a masters degree in geology from UCLA and received his Ph.D. in evolutionary paleontology from Cornell University. However, according to a video clip originally from the Bad Religion official website and also available from The Cornell Evolution Project homepage, the PhD thesis was officially a Zoology PhD thesis, supervised by William B. Provine at Cornell University. The thesis was entitled "Monism, Atheism and the Naturalist Worldview: Perspectives from Evolutionary Biology". It is described as being essentially an evolutionary biology PhD but having also relevance to history and philosophy of science.

Greg Graffin currently resides in Los Angeles, California and is teaching life science at UCLA.