A total of 40,000 private donors contributed to the centre, developed at the Austin Hospital at 145 Studley Road.
Sam Stynes, wife of the late footballer Jim will be the centre’s new ambassador.
Newton-John told the Herald Sun complementary therapies such as acupuncture, massage, yoga, meditation and homeopathy helped her through her own battle in the early 1990s.
She cited her late mother, Irene’s advice on lending her name to the project, reciting the words “if it helps people you should do it”. Newton-John’s late father, Brinley, died of cancer.