Johnstone was born in Germany and is of Scottish descent.[3]
With his father in the Army, Johnstone was born in Germany. Johnstone has lived in England since he was very young; as a junior, he played for Stanningley Amateur Rugby League Club. He attended Pudsey Grangefield School and represented the City of Leeds sprinting team at Indoor athletics.
Playing career
Wakefield Trinity
Johnstone plays at Wing or Centre. He is noted as one of the fastest players in the game. He has also represented England at under 19's level. He made his professional début for Wakefield Trinity against Leeds in 2014 during a Boxing day friendly at Headingley. He made his full Super League début for an injury-hit Wakefield Trinity side in their 2015 Round 7 defeat by Wigan. He played 13 times in his first season at Wakefield Trinity, scoring 9 tries. He scored his first Wakefield Trinity try against St Helens in a 44-4 defeat. In his second season 2016 he scored one length of the field effort that was considered to be the try of the season.
The Wakefield Trinity club signed him up on a long four-season deal, an unprecedented step by the club. Arguably the brightest young talent in English Rugby League, Johnstone is widely regarded as one of the fastest players in the Super League if not the fastest and is without a doubt one of the best finishers. Johnstone received his first International call up against France in 2018, he scored a sensational hat-trick of tries on his debut. Johnstone was one of the favourites in 2019 to become Super League's top try-scorer and he appeared well motivated to achieve that accolade until injury struck.[4]
In round 1 of the 2021 Super League season, Johnstone scored two tries and received the man of the match award in Wakefield's 28–22 loss against Leeds.[5]
Catalans Dragons
On 5 July 2022, Johnstone signed a two-year deal to join the Catalans Dragons starting on 2023.[6]
On 15 July 2022, Johnstone was ruled out for the remainder of the 2022 Super League season with a groin injury.[7]
In round 1 of the 2023 Super League season, Johnstone made his club debut for Catalans against his former club Wakefield Trinity. Johnstone would score a hat-trick in Catalans 38-24 victory. In round 5 of the competition, he scored another hat-trick in Catalans 26-12 victory over Hull Kingston Rovers.[8] On 1 April 2023, he scored his 100th career try in a 22–18 win against Castleford Tigers.[9]
In round 13 of the 2023 Super League season, Johnstone scored two tries against his former club Wakefield Trinity as Catalans won 36-6.[10]
The following week, Johnstone scored a hat-trick in Catalans 46-22 victory over Wigan at Magic Weekend.[11]
On 14 October 2023, Johnstone played in Catalans 2023 Super League Grand Final loss against Wigan.[12]
Wakefield Trinity (re-join)
On 17 May 2024, it was reported that he had signed for Wakefield Trinity on a four-year deal.[13]
Johnstone has suffered two career-threatening anterior cruciate ligament (ACL) knee injuries, one in each leg. The first was in 2017, the second was in 2019 from which he recovered in time to take part in 2020's Super League XXV.[citation needed]
