His family says the 77-year old, who has been a Douglas County Commissioner since 1997, passed away peacefully early Monday morning.
He had been fighting complications of diabetes, and the family says he became ill Sunday before being taken to a hospital overnight.
In March, his physician daughter Maureen, who is also a Douglas County Commissioner, said her father was diagnosed with lung cancer, and the family says he had successful surgery for that in August.
Boyle, who also served as Douglas County Election Commissioner before running for Mayor, and his wife Anne, formed a dynamic political duo as she was a Democratic Party State Chair and had been elected to the Nebraska Public Service Commission.
The family says details about funeral services will be soon be released.
(Pictures from Douglas County Government and VisitOmaha)