William Clay

William Clay, Willie Clay, Bill Clay, or Billy Clay may refer to:

Politicians

 * Bill Clay (William Lacy Clay, Sr., born 1931), politician from the state of Missouri
 * Lacy Clay (William Lacy Clay, Jr., born 1956), politician from the state of Missouri
 * Sir William Clay, 1st Baronet (1791–1869), English merchant and MP for Tower Hamlets

Sports

 * William Clay (footballer) (born 1883), footballer
 * Willie Clay (born 1970), former American football player
 * Billy Clay (born 1944), American football cornerback
 * William Clay (cyclist) (born 1973), American track cyclist
 * Bill Clay (baseball) (1874–1917), American baseball player

Others

 * William Clay (industrialist), early user of the Bessemer process in Liverpool
 * William Keatinge Clay (1797–1867), English cleric and antiquary