On June 29, 2001, Lennon was named as an auxiliary bishop of Boston; he was ordained as a bishop on September 14, 2001. From 2001 until April 2006, Lennon served as a bishop in Boston, holding a variety of positions, including vicar general.
After Bernard Francis Law resigned his position as Archbishop of Boston in December 2002 amid the church sex scandal, Lennon became very important in leading the troubled archdiocese through the turbulent times as he was the interim leader. He served as the Apostolic Administrator of the archdiocese between Law's resignation and the accession of its new Archbishop, Sean O'Malley.
On 5 April 2006, Lennon was appointed by Pope Benedict XVI as the replacement for Bishop Anthony Pilla in the Roman Catholic Diocese of Cleveland. He became the 10th bishop of Cleveland in an installation ceremony on 15 May 2006.
Lennon's appointment as Apostolic Administrator of the Boston Archdiocese, following the resignation of Cardinal Law, brought criticism from some sex-abuse victims' groups.
This criticism increased after Lennon's appearance in the Frontline Documentary "Hand of God." The movie documents the history of a Salem, Massachusetts sex scandal and its effects on the film maker's own family. Church figures are shown minimizing the scandal, lying about their knowledge of the priest involved in the scandal, and refusing to speak with victims. Lennon closes the Salem parish despite the fact it is not losing money for the Church. Then, when the movie's filmmaker attempts to film the administrative building where his brother reported his own sexual abuse, Lennon exits the building, shoves the camera, declares he won't "feel bad about this" after being told why the filmmaker wants to film the building's exterior, attempts to avoid any discussion of the sex scandal by refusing to talk about anything other than the Church's private property rights, and responds to the film maker's claim that he doesn't care by calling the filmmaker a "sad little man."
---Wikipedia
Was he a dirty vicar?