Collett also played international rugby for the British Isles during the 1903 tour of South Africa but was never selected for the England national team.
In 1898, Collett was part of the Cambridge team that faced Oxford University in the Varsity Match, winning his first and only sporting 'Blue'.
After Oxford lost Nelson, their captain, to an ankle injury, Cambridge took control of the forward positions and won the game comfortably.
Collett played in 20 of the 22 match tour, including all three Test games against the South African national team.
During the First World War, Collett was touch judge for a rugby match played between British troops from the Gloucestershire Regiment, which included club county and international players.