Boyle started her career in elective office as a state legislator representing Cleveland Heights (Ohio District #9) in 1978. She was Elected Majority Whip in the Ohio House of Representatives in 1982. Following that, she served on the Board of County Commissioners of Cuyahoga County, Ohio for twelve years. She was the first woman ever elected to a non-judicial county office in Cuyahoga County. She is married to the former Vice-President of Cleveland State, Jack Boyle.
Boyle was a candidate for the United States Senate in 1994 to replace the retiring Howard Metzenbaum, but she was defeated in the Democratic primary by Joel Hyatt. Republican Mike DeWine eventually was elected to the Senate seat in November 1994. In 1998, she was the Democratic nominee for U.S. Senate to replace the retiring John Glenn. She was defeated by then Ohio Governor George Voinovich. She was the first (and still only) woman nominated by a major party for the Senate from Ohio. Boyle also ran for Treasurer of State in 2002 against Joseph T. Deters, which she lost.
Boyle is the mother of Ohio politician Jim Boyle and three other children: Catherine Boyle, John Boyle, and Peter Boyle.