In a land area of 10,291 square kilometers, the diocesan territory covers the whole civil district of Uttara Kannada.
Languages spoken in the diocese are Konkani, Kannada, Marathi.
The civil district of North Kanara (Uttara Kannada) was part of the Archdiocese of Goa till September 19, 1953 when the new Diocese of Belgaum was erected. Two civil districts, Belgaum and North Kanara, were separated from the Archdiocese of Goa and two other civil districts, Dharwad and Bijapur, were taken from the Diocese of Poona to form the Diocese of Belgaum.
The Diocese of Karwar, comprising the whole civil district of Uttara Kannada, was carved out of the Diocese of Belgaum and erected as Diocese of Karwar by the Decree Christi Missum of Pope Paul VI dated Jan. 24, 1976. Bishop William Leonard D'Mello was appointed the first Bishop of Karwar on the same day. He was ordained and installed as the first Bishop of Karwar on April 29, 1976.
After zealously shepherding the new diocese for nearly 30 years, Bishop William D'Mello resigned. On Feb. 24, 2007, Pope Benedict XVI appointed Msgr. Derek Fernandes of the Clergy of Belgaum diocese to be the new Bishop of Karwar. Bishop Derek Fernandes was ordained and installed as the Bishop of Karwar on April 20, 2007.
Patron Saint of the diocese is St. Joseph.