William Parsons may refer to:
Arts and entertainment William Parsons (composer and copyist) (fl.1545–1563), English Renaissance composer and copyist from Wells William Parsons (composer and musician) (1745/6–1817), Master of the King's Music William Parsons (poet) (died 1828), English writer associated with the Della Cruscan movement William Parsons (actor) (1736–1795), British actor and painter
Sports William Parsons (footballer) (1877–?), Anglo-Spanish footballer Bill Parsons (born 1948), baseball player
Nobleman Sir William Parsons, 1st Baronet of Langley (c.1636–c.1662), of the Parsons baronets Sir William Parsons, 1st Baronet of Bellamont (died 1650), surveyor general of Ireland and member of parliament Sir William Parsons, 2nd Baronet of Bellamont (died 1658), Earl of Rosse Sir William Parsons, 2nd Baronet of Birr Castle (1661–1741), Anglo-Irish politician Sir William Parsons, 4th Baronet of Birr Castle (1731–1791), Irish politician William Parsons, 3rd Earl of Rosse (1800–1867), Lord Rosse, Irish astronomer William Parsons, 5th Earl of Rosse (1873–1918), Irish peer and British Army officer Brendan Parsons, 7th Earl of Rosse (William Clere Leonard Brendan Parsons, born 1936), worked for the United Nations
Others William Barclay Parsons (1859–1932), American civil engineer William E. Parsons (1872–1939), American architect and city planner William Sterling Parsons (1901–1953), American naval officer and atomic bomb weaponeer aboard Enola Gay William Parsons (surveyor) (1701–1757), English Surveyor-General of Pennsylvania Province, founder of Easton, Pennsylvania. William W. Parsons (academic administrator) (1850–1925), president of Indiana State Normal School, later known as Ball State University William W. Parsons (NASA), former director of the NASA John F. Kennedy Space Center, & Space Shuttle Program manager William Henry Parsons (New York activist) (died 1935), headed the New York Society for the Suppression of Vice William Henry Parsons (colonel) (1826–1907), American newspaper editor, legislator, and Confederate colonel