William Bain

Bill Bain or William Bain may refer to:


 * Bill Bain (consultant) (1937–2018), American management consultant, founder of Bain & Company
 * Bill Bain (American football) (born 1952), American football player
 * Bill Bain (director) (1929–1982), Australian-born television director
 * William Bain (lecturer), academic
 * William Bain (Royal Navy officer) (1771–1853), Scottish Royal Navy officer, inventor, and steamship captain
 * William Alexander Bain (1905–1971), Scottish pharmacologist
 * William J. Bain (1896–1985), Seattle architect, co-founder of NBBJ
 * Willie Bain (born 1972), Scottish politician