Ray was born as Mary Josephine Arsenault in Bloomfield, Prince County, Prince Edward Island, Canada, on 17 May 1895, to parents Robert Fabien Arsenault (1851–1903) and Lidie Ann Blanchard (1858–1910). She had six siblings: Jean Jacques (1884–1904), François (born 1886), Célina (born 1887), Agnes (born 1888), André Edmond (born 1893), and Joseph Paul (1897–1974). When she was 3 years old, the family moved to Maine, USA, where her parents searched for work. Her father died in November 1903, when she was 8 years old. At the age of 14, she moved back to Canada with her mother, who passed away within the year, in September 1910, when Ray was 15 years old. Not long after, the siblings returned to the United States, where she started working as a housekeeper and store clerk to support herself.
In 1923, she married Walter Howard Ray (1893–1967). The couple had two sons: Robert Ray (1923–2017) and Donald K. Ray (1925–2015). At the age of 72, following the death of her husband, she moved from Anson, Maine to Florida. At the age of 80, she moved to Chelmsford, Massachusetts.
In 2002, she decided to move into the Maplewood Nursing Home in Westmoreland, New Hampshire, to be near her children. She was taking part in the New England Centenarian Study. She was an avid Red Sox fan and collected Red Sox merchandise. Her 108th birthday cake had a Red Sox symbol on it. At the age of 114, she was still playing cards. It was reported she was physically active until about two weeks before her death, even having an interview a week before her death.
Ray passed away at a nursing home in Westmoreland, New Hampshire, USA, on 7 March 2010, at the age of 114 years, 294 days. She was survived by two sons, eight grandchildren, 13 great-grandchildren and five great-great grandchildren.