Deledio attended Kyabram High School and Caulfield Grammar School. During his youth,
he was both a promising cricket and football player. David Hookes, then the coach of the
Victorian Bushrangers, invited Deledio to join the state team, but he declined this offer to
concentrate on any future AFL career. Brett was enrolled to attend Caulfield Grammar
School, which is the same school that hosted the likes of Chris Judd and Andrew Walker.
Unfortunately after only a handful of days at the school it is believed that he pulled out due
to the pressurised season, which was ahead of him in 2005. Brett Deledio went on to study
with a tutor and won the Rising Star award for the best young star of 2005.

He soon debuted for the Murray Bushrangers as the team's youngest squad member, before
being selected with the first overall selection in the 2004 AFL Draft On 31 August 2005,
Deledio was awarded for his outstanding season with the AFL Rising Star award, receiving
43 of a possible 45 votes. Deledio followed his Rising Star Award by also winning the AFL
Players' Association Best First-Year Player Award, voted by his peer players. Deledio was
also considered to be the fastest or one of the fastest players in the league, winning the 2005
AFL Grand Final Sprint.Capping off his debut season, Deledio was chosen to represent
Australia in the International Rules series for 2005, becoming the youngest Australian player
in the competition's history.

Deledio played 21 out of 22 matches in 2006 and was again a consistent performer only
missing the one game with an injured knee. He was often the target of attention from the
opposition taggers, due to his abilities, and found it difficult to break the tag. However he still
produced impressive figures, averaging 18.8 possessions and 6.5 marks a game.

In 2007, Deledio developed into a highly versatile player, who often provided difficult match
up's for the opposition. He often played multiple roles from the forward line to midfield to
rebounding from the backline. In the forward line he used his speed and judgment well to
lead into space and take strong marks and kicked 21 goals for the season. Out of defence,
he often used his electric pace to provide run and carry and deliver pinpoint passes into the
forward line. Deledio averaged 18.4 possessions and 5.4 marks a game. Deledio's best
game of the season was arguably during the Round 19 win vs Collingwood. Deledio kicked
a career-high 5 goals, which earned him 3 brownlow votes.

Deledio started off the 2008 season in the forward line in Round 1, but has pushed up the
ground since then. He surpassed 30 possessions for the first time this year, achieving the feat
in Round 6 against Hawthorn, in Round 10 against Sydney and in round 11 against Adelaide.
So far this season he has developed his game further, averaging 24.6 possessions and 1 goal
a game.Deledio won the AFL Army Award for his courage shown in round 7 against the
Saints when he flew backwards into a pack to take a mark and heavily collided with a Saints
player.He was also announced in the 40 man All Australian squad for 2008.Deledio was
rewarded for his consistent season with the Richmond Best and Fairest. Deledio polled 250
votes to take out the award.