William T. Piper, American engineer and businessman, founded Piper Aircraft (born 1881)

William Thomas Piper Sr. was an American aviation and oil industry businessman. He was the founding president of the Piper Aircraft Corporation and led the company from 1929 until his death in 1970. He graduated from Harvard University in 1903 and later became known as "the Henry Ford of aviation".

Piper Aircraft, Inc. is a manufacturer of general aviation aircraft, located at the Vero Beach Regional Airport in Vero Beach, Florida, United States and owned since 2009 by the Government of Brunei. Throughout much of the mid-to-late 20th century, it was considered to be one of the "Big Three" in the field of general aviation manufacturing, along with Beechcraft and Cessna.