Spears was born in McComb, Mississippi, to English mother Lilian Irene Portell (1924–1993), and Barney O'Field Bridges (1919–1978), an American G.I.. In 1945, her parents met and married in Portell's native London. Spears's maternal great-grandfather, Edward Portelli, was a Maltese immigrant to the United Kingdom. Spears has an older brother, Barry "Sonny" Bridges (born 1951). Their older sister, Sandra Bridges Covington (1947–2007), died of ovarian cancer.
In 1975, she married James "Jamie" Spears. They were divorced in 2002 and reconciled in 2010. Jamie and Lynne Spears have three children: son Bryan James (born 1977) and daughters Britney Jean (born 1981) and Jamie Lynn Marie (born 1991). They also have four grandchildren: grandsons Sean Preston Federline (born 2005) and Jayden James Federline (born 2006) from Britney and granddaughters Maddie Briann Aldridge (born 2008) from Jamie Lynn and Sophia Alexandra Spears (born 2011) from Bryan.