The former test wicketkeeper had intended to step down in mid-2017 but announced he is vacating the role immediately.
"This is my own decision and no-one within Cricket Australia has pressured me or even suggested that I should do this," Marsh said in a media release.
"Clearly, though, it is time for some fresh thinking, just as it is for our Test team to welcome some new faces as we build for the future."
Image: Rod Marsh, right, with Australia captain Steve Smith
Photograph: Paul Kane/Getty Images
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