Gillespie was selected for the 1903 British Lions tour to South Africa and finished the tour as the top Test scorer for the touring team. He played in 19 matches during the tour including all three test games against South Africa. He scored 13 conversions and a single try on the tour, and amassed four points in the first Test, the British failing to score in the second and third tests.
Referee career
He later became a successful referee, including two vs internationals, one in 1907, and the other in 1911.