Commencing his umpiring career with the Western Australian Premier Cricket competition in the early 2000s, Johnstone went into his debut with 174 First Grade matches to his name which places him 18th on the list of First Grade Umpires in Western Australia.
In a testament to his dedication, Johnstone passed 350 total WACA Grade matches earlier this season whilst he has also officiated in the last five Premier First Grade Finals.
Joining the Cricket Australia Development Umpire Panel this season, Johnstone is no stranger to the international and national umpiring scene having made his List-A debut in December 2010 at the WACA.
In total Johnstone has stood in four One-Day domestic fixtures and been appointed to a further four games as Third Umpire.
In January 2011 Johnstone made his Women’s One-Day International debut at the WACA in the fixture between Australia and England before returning two days later to officiate in the third One-Day International game of the Series.
He was appointed to all three of the Women’s Rose Bowl Series fixtures between Australia and New Zealand in January 2012, before again officiating the same teams in two One-Day Internationals in December 2012.
At the close of the 2016/17 season Johnstone was appointed to the Under 19 International Series in Hobart between Australia and Sri Lanka.
This complemented an Under 19 International Test Match earlier in his career in April 2009 where Australia hosted India at the WACA.
Johnstone attended his first Cricket Australia Under 17 National Championships in 2006/07 before starting the first of five Under 19 National Championships from 2008/09 onwards.
In total Johnstone has officiated in 15 Women’s National Cricket League matches; nine women’s domestic T20s (four of which in the WBBL tournament) and 15 Toyota Futures League fixtures.
Off field Johnstone is an active member of the Western Australia Cricket Umpires’ Association, sitting on the committee of management and having served as Secretary for two seasons in 2009/10 then again in 2010/11.
Johnstone debuts alongside Paul Wilson and Match Referee Bob Parry.