William Thomas Stuart Porterfield (born 6 September 1984) is an Irish former cricketer and a former captain of the Ireland cricket team. He played first-class cricket for Gloucestershire and Warwickshire. A left-handed batsman, he played for Ireland from 2006-2022, and has captained Ireland at all levels from Under-13 and is considered one of the greatest Irish cricketers of all time. During Afghanistan T20I series in March 2017, he passed 1,000 runs in T20Is and became the first player from Ireland to do so. In May 2018, he was named as the captain of Ireland's squad for their first ever Test match, against Pakistan. He announced his retirement from international cricket on 16 June 2022.