The Finley product was one of the Hawks' best players in a disappointing 2019 season with Brain finishing runner-up in the club’s best and fairest vote count.
The Hawks finished 10th this year with a six and 12 record, with player turnover and a long list of injuries seeing the side fall well short of its 2018 standard where it came within a win of the flag.
Barooga president Marcus Fry hopes the rookie coach, who will continue playing, will be able to bring the best out of an inexperienced roster.
“From a club point of view, we know Zac has played at a pretty high level and has a good knowledge of the game,” Fry said.
“We have a lot of players under the age of 22 and we believe he’s the man that can take them and teach them what’s required to get to the next level.
“We looked far and wide and sometimes you find something under your nose that you weren’t even looking for.
“We also send a big thanks to our outgoing coach James Hazelman for his tireless work over the last three years as seniors' coach taking us to a grand final in 2018.”
Hazelman is set to take a year off to recover from a knee operation with the 300-gamer hopeful of making to a return to the field in future.
Brain was unable to be contacted due to being overseas for a holiday.
Barooga also unveiled the coaches of the lower grades with David Trenerry and Liam Mathers staying on at the club as the reserves' and Under-14s' coaches respectively.
The Under-17s will be headed by John Lucci who joins the Hawks after a successful spell as the Under-17s' coach at Strathmerton. Lucci replaces Jason Brooks.