Dunkley was born in Sydney, the second of three children to footballer Andrew and his wife Lisa. After Andrew retired from AFL football in 2002, the family returned south to country Victoria and lived on a farm near Yarram in the Gippsland region. During his time playing for Gippsland Power, Dunkley developed into a promising leader, and his strong overhead marking skills, along with his ability to win the contested ball, had many comparing him to Sydney star Luke Parker. He also spent time with Sydney's youth academy and played six games for 's VFL team in 2015. In the lead-up to the 2015 AFL draft, Dunkley attracted keen interest from a number of clubs, especially his father's former club Sydney, but when the Western Bulldogs bid for Dunkley with the 25th selection, Sydney chose not to match the bid. After losing players like Nick Malceski and Adam Goodes, the club were looking for players with strong kicking skills and although Dunkley was under serious consideration, it was felt that his kicking skills needed improvement. He thus became the first player under the new father–son drafting rules to have a draft bid placed on him which was not matched by his father's former club. He graduated from Gippsland Grammar School in 2014 and spent 2015 working at the school as a teachers assistant prior to being drafted
AFL career
Dunkley made his AFL debut in round 1, 2016 against. He also scored his first AFL goal in that match. After his performance against in round 20 where he recorded nineteen disposals, four tackles, three clearances, and three inside-50s, he was the round nomination for the Rising Star. Dunkley would then go on to play a key role in the club's amazing finals campaign, showing composure beyond his years on the biggest stage. He kicked two goals in the 47-point upset of in the elimination final in Perth. Then the following week against in the semi-final, Dunkley was rated among the Bulldogs' best players, kicking a crucial goal in the second quarter as well as gathering 23 possessions in a memorable 23-point win. In the heart-stopping preliminary final win against, Dunkley again recorded over 20 possessions, and in the grand final against his father's side, he gathered 15 disposals and seven tackles. At 19, he was the youngest player in the premiership side.