Son of William McIlroy, 7912 Parnell Avenue, Chicago, USA.
Lived 11 Carwood Street, Greenock. Worked as an apprentice shipwright.
Described as 5 foot, 7 inches tall with a fair complexion, dark haired and brown eyed. He was a Protestant by faith. He was unable to swim.
Joined 18th March 1912. Mobalised 19th August 1914.