Bishop Dewane was born in 1950, of devout Irish-Catholics. He attended the University of Wisconsin where he earned a B.S. in Social Sciences. He then earned a M.A. in International Administration from The American University. After graduation, Bishop Dewane worked for NBC and PepsiCo.


Bishop Dewane began his studies for the priesthood at Notre Dame University, completing his studies at the Pontifical Gregorian University in Rome. In 1988, Bishop Dewane was ordained and appointed to the Diocese of Green Bay as an assistant pastor. He also worked for the diocesan Tribunal.


In 1991 Bishop Dewane became a delegate for the Vatican as a member of the Permanent Observer Mission to the United Nations. Bishop Dewane currently serves on the U. S. Catholic Conference of Bishops. On July 25, 2006 Bishop Frank J. Dewane was installed as bishop of the Diocese of Venice in Florida.