Irwin played a total of 43 games with North Melbourne in the Victorian Football Association (VFA) over three seasons (1919–1921), and scored 34 goals.
Irwin started his career as a defender, and played in the back pocket when Essendon won the 1923 premiership.
In 1924, he moved from the backline to the forward pocket, kicking 10 goals against St Kilda, at Windy Hill, on 14 June 1924.
In total, Irwin played 78 games for Essendon, kicking 102 goals, and was a four-time Victorian interstate representative.
In 1929, along with Geelong's Eric Fleming, St Kilda's Wal Gunnyon, Essendon's Frank Maher, and Chris Gomez, and Richmond's Fred Goding, and George Rudolph, all of whom went to Oakleigh without a clearance from the VFL (in doing so all were automatically disqualified from the VFL for three years).