Harrington was born as Elsie Emma Cleiss in Schenectady, New York, USA, on 4 February 1911. Her parents were George Cleiss (1881–1955) and Emma Kretchmann (1884–1942), both German immigrants. She had four siblings: George W. (1904–1963), Margaret Breitenstein, Dorothy Anna Quante (1913–1996) and Mildred Westover (1916–2007). She was a graduate of Schenectady High School.

In 1934, she married Myron Vincent Harrington (1907–1995). The couple had three sons: Myron, Russell and James.

Harrington passed away in Schenectady, New York, USA on 14 March 2021 at the age of 110 years, 38 days. She was survived by her three sons, 9 grandchildren and 12 great-grandchildren.