Haddin, who played 66 tests despite Adam Gilchrist blocking his path into the side until he was 30, has cut his coaching teeth with the Australia A side and Islamabad in the Pakistan Premier League since retiring in 2015.
The 39-year-old, who will work under head coach Darren Lehmann, said he was looking forward to working with what is a relatively inexperienced Australia team.
"I grew up in an era of players like Andrew Symonds and Ricky Ponting who gave Australian cricket a real identity in the standards of world class fielding," he said in a news release.
"They were the type of players who took it personally if the team wasn't fielding well and that created a level for the rest of the group to aspire to.
"I want to hold this group accountable to that kind of standard and I believe we have the talent to do that."
Former test all-rounder Blewett has stepped down to take up a role as under-19 coach at the South Australian Cricket Association, where he played Sheffield Shield cricket for 15 years.
"It has been fantastic having Greg involved in the side," said Lehmann.
"Brad had a wonderful career as a player for Australia and will bring a multi skill set to our environment.
"His primary focus will be on fielding, carrying on the good work that Greg has done, but will also work very closely with our wicket-keepers."
Australia next play two tests in Bangladesh in August and September before a one-day series in India and the home Ashes series around the New Year.
(Reporting by Nick Mulvenney, editing by Greg Stutchbury)
