William Walker (May 8, 1824 - September 12, 1860) was a U.S. physician, lawyer, journalist, adventurer, and soldier of fortune who attempted to conquer several Latin American countries in the mid-19th century. He held the presidency of the Republic of Nicaragua from 1856 to 1857 and was executed by the government of Honduras in 1860.

William Walker (May 6, 1809 – September 24, 1875) was a Baptist song leader, shape note "singing master", and compiler of three shape note tunebooks¹. He was born in South Carolina, and grew up near Spartanburg. Walker married Amy Golightly.

William Walker MVO (1869-1918) was an English diver famous for shoring up the southern and eastern sides of Winchester Cathedral. In his time, William Walker was the most experienced diver of Siebe Gorman Ltd. Working in water up to a depth of 6 m between 1906-1911, he shored up the Cathedral using more than 25,000 bags of concrete, 115,000 concrete blocks and 900,000 bricks.