William Clarke (March 21, 1951 - November 3, 1996) was an American blues harmonica player. He was chiefly associated with the Chicago blues style of amplified harmonica, but also incorporated elements of soul jazz and swing into his playing.
Born in Inglewood, California, United States, Clarke played guitar and drums as a youngster and learned the blues through The Rolling Stones records. He began playing harmonica in 1967 and played locally in Los Angeles, while he held a day job as a machinist. He soon struck up an association with George "Harmonica" Smith; the pair began playing regularly together in 1977, lasting until Smith died in 1983.
Clarke began releasing albums in 1978 on small local record labels. From 1985 to 1988, Rick Holmstrom toured and played with Clarke. In 1987, Clarke was nominated for a W.C. Handy Award for his record Tip of the Top, and after sending a demo tape to Alligator Records, he secured a national recording contract. His debut for Alligator, Blowin' Like Hell, arrived in 1990, and he followed the release with international touring. "Must Be Jelly", a song from the album, won the Handy Award for Blues Song of the Year.
Clarke was touring in March 1996 when he collapsed on stage at a date in Indianapolis. He was diagnosed with congestive heart failure, and as a result lost weight and cut back on alcohol and drugs. These measures were not sufficient to keep him healthy; he collapsed again in November, at a concert in Fresno, and died of a bleeding ulcer, at the age of 45, the following day.