Started playing golf at the age of four when his father, a single-figure handicapper, took him out to a local field to hit balls, before becoming a member at North Middlesex GC at the age of nine. Made the climb to the England Boys team via his county team and won the Boys Home Internationals in 2007 alongside such players as Tommy Fleetwood, Matt Haines and Matthew Nixon. Turned pro at the age of 20 and started on the Jamega Pro Golf Tour. Earned five Challenge Tour invites in 2010 and took advantage, earning a category 13 for 2011. Looked down and out midway through the 2011 season but took advantage of an invite to the ECCO Tour Championship presented by Thomas Björn and Mercedes Benz, his ninth place finish enough to seal berths in the lucrative Kazakhstan Open and M2M Russian Challenge Cup, where he finished second. His meteoric rise continued at the season-ending Apulia San Domenico Grand Final, where a stunning performance and a third place finish earned him a card for The European Tour 2012 International Schedule. Commonly known amongst friends as “beef”, Johnston is a keen Arsenal fan and also a follower of basketball.