Bruce, who has been a development coach at the Hawks since retiring as a player midway through the 2012 season, joins Luke Beveridge, Brendon Bolton and Brett Ratten as assistants to Alastair Clarkson.
The former Melbourne and Hawthorn midfielder's promotion was one of four coaching changes announced by the Hawks on Monday.
Adem Yze has been appointed as a full-time development and specialist coach, after filling the role part-time this season.
His chief focus in 2013 was goal-kicking.
Box Hill premiership coach Damian Carroll will vacate his role at Hawthorn's VFL affiliate, and become head coach of the club's development academy.
Carroll coached Box Hill for three seasons, after switching from TAC Cup team Gippsland Power at the end of 2010.
He will be replaced at Box Hill by Marco Bello, who this season coached the Northern Knights to a TAC Cup semi-final.
Bello played in five premierships with SANFL club Central District, including the 2001 team coached by Clarkson.
Bruce played 224 games for Melbourne and 10 for Hawthorn during a 13-year AFL career, retiring in July 2012 due to a back injury.
Twitter: @AFL_MarkM
