He was born in Kojonup in Western Australia to Terrence and Mary Moir who were farmers and had three siblings, Margaret, Andrew and Catherine.
[1][2] On completion of high school, he studied biochemistry at the University of Western Australia with one of his microbiology lecturers being Nobel Prize winner Dr Barry Marshall, who discovered that H. pylori cause ulcers.
[1][2] Moir immigrated to the United States in 1994 to work in Rudolph Tanzi's laboratory at Harvard University as an Alzheimer’s biochemist.
[3] He continued working for Tanzi as a post-doctoral fellow and would eventually become an assistant professor in neurology at Harvard Medical School and the Massachusetts General Hospital and his own laboratory at the institution.
[3] The next step was testing the theory in Alzheimer's and in healthy brain tissue; he attempted to publish the results in Science and three other journals and was rejected, but finally succeeded in 2010.
[3] In 2006 he received funding from the NIH/National Institute on Aging (NIA) for targeting cross-linked amyloid protein species as a therapy for Alzheimer's Disease.