William Sproul may refer to:

• William Cameron Sproul (1870-1928), Governor of Pennsylvania
• William H. Sproul (1867-1932), U.S. Representative from Kansas

• Bulbophyllum paranaense
• Bulbophyllum pardalinum
• Bulbophyllum pardalotum
• Bulbophyllum parviflorum
• Bulbophyllum parvum
• Bulbophyllum patella
• Bulbophyllum patens
• Bulbophyllum pauciflorum
• Bulbophyllum paucisetum
• Bulbophyllum paululum
• Bulbophyllum pecten-veneris
• Bulbophyllum pectinatum
• Bulbophyllum pelicanopsis
• Bulbophyllum peltopus
• Bulbophyllum pemae
• Bulbophyllum penduliscapum
• Bulbophyllum pendulum
• Bulbophyllum penicillium
• Bulbophyllum peninsulare
• Bulbophyllum pentaneurum
• Bulbophyllum pentastichum
• Bulbophyllum peperomiifolium
• Bulbophyllum peramoenum
• Bulbophyllum percorniculatum
• Bulbophyllum perductum