Dunk made his debut for Queensland in December 2009, having been selected in the Twenty20 team. 2009-10 was a breakout season for Dunk, playing 9 games, highlighted by an innings of 70 not out off 40 balls. He made his Sheffield Shield debut for Queensland in October 2010, playing as a specialist batsman (Chris Hartley retained selection as Queensland’s wicket-keeper).

In 2012, Dunk moved to the Tasmanian Tigers. On 18 October 2014 he scored an unbeaten 229 against Queensland in the domestic one-day competition, surpassing David Warner’s 197 and became the first one-day double century in Australian Domestic cricket.

He made his Twenty20 International debut for Australia against South Africa on 5 November 2014.

Dunk has been a standout player Australia’s domestic Twenty20 competition, the Big Bash League, with Dunk being the 4th highest run scorer of the tournaments history. He has been the top run scorer of a season on two occasions, the equal most by any player in the BBL. Dunk has played for four of the eight franchises throughout his BBL career, currently playing for the Melbourne Stars. He has also played for both Karachi Kings and Lahore Qalanders in the Pakistan Super League. In September 2019, he was named in the squad for the Nelson Mandela Bay Giants team for the 2019 Mzansi Super League tournament.

In July 2020, he was named in the St Kitts & Nevis Patriots squad for the 2020 Caribbean Premier League.