Olivia Newton-John, AO, OBE (born 26 September 1948) is an English-Australian singer, songwriter, and actress. She is a four-time Grammy award winner who has amassed five number-one and ten other Top Ten Billboard Hot 100 singles, and two number-one Billboard 200 solo albums. Eleven of her singles (including two platinum) and fourteen of her albums (including two platinum and four double platinum) have been certified gold by the RIAA. She has sold an estimated 100 million records worldwide, making her one of the world's best-selling artists of all time. She starred in the musical film Grease, and its soundtrack is one of the most successful in history.

Newton-John has been a long-time activist for environmental and animal rights issues. In remission from breast cancer from 1992 until her newest diagnosis (see below), she has been an advocate for health awareness becoming involved with various charities, health products, and fundraising efforts. Her business interests have included launching several product lines for Koala Blue and co-owning the Gaia Retreat & Spa in Australia.

Newton-John has been married twice. She is the mother of one daughter, Chloe Rose Lattanzi, with her first husband, actor Matt Lattanzi. She remarried, to John Easterling.