Ginn failed in his bid to become the first Australian man to win gold in four different Olympics when his boat finished second to Britain in the blue riband coxless fours race in London earlier this year.
The 37-year-old, who won gold in Atlanta, Athens and Beijing but missed out on the Sydney Olympics through injury, had not ruled out going to a fifth Games in Brazil in 2016.
A member of Australia's original "Oarsome Foursome", Ginn will be in charge of "Integration" as one of two head coaches for the Australia team.
"I am lucky to have been part of one the world's most successful rowing teams over the last two decades as an athlete and I am very excited to continue my involvement - this time from the head coach position," he said.
"We were very successful in London with five medals, but we have bigger goals and I am passionate about our sport and its ongoing success.
"It is a great honour to be offered this role and a fantastic opportunity to have an impact and be part of implementing a programme that will consistently produce gold medals."