William Patrick Duggan (12 March 1950 – 28 August 2017) was an Irish international rugby union player.
He won 41 Irish caps, the first in 1975 and finished his international career in 1984 as captain.
He toured New Zealand in 1977 with the British and Irish Lions, and at the time played club rugby for Blackrock College RFC, after commencing his career with Sunday's Well RFC in Cork.