By the Apostolic Brief dated June 12, 1923 of Pope Pius XI, the Diocese of Calicut was erected:
a. by separating from the Diocese of Mangalore that portion of the Malabar district which till then was under it
b. by adding on to it the Wayanad Taluk, till then under the Diocese of Mysore
c. likewise adding also the area west of the watershed of the Walluvanad Taluk, till then under the Diocese of Coimbatore
d. by a Decree of the S. Cong. de Propaganda Fide dated January 12, 1960, the Hosdurg Taluk was till then part of the Diocese of Mangalore was added to the Diocese of Calicut.
The extent, therefore, of the diocese may be described as the whole of the former Malabar district up to the Ponnani river, part of Palghat district and the area of the watershed of Walluvanad Taluk, with the addition of the present Hosdurg Taluk to the north. At the time of erection it numbered in all, 8000 Catholics, the majority of whom resided in the three old stations along the shore of the Arabian Sea, viz, Calicut, Tellicherry and Cannanore. Mainly due to the steady influx of information from Travancore and Cochin, the total Catholic population had risen by 1953 to 91,384 of which 17,217 were Latins and the rest Syrians. On March 19,1954 with the erection of the Diocese of Tellicherry the faithful of the Oriental Rite passed under the Jurisdiction of the Ordinary of the Diocese.
For the first 32 years of its existence the Diocese of Calicut had been entrusted to the Mangalore-Calicut mission of the Society of Jesus; but with the erection of the independent Vice-Province of Mangalore on May 29, 1955 the territory of the Diocese of Calicut was temporarily assigned the Madurai province of the Society of Jesus, pending the erection of the independent Vice-province of Kerala, which took place on September 27, 1960. The vice-Province became Kerala Jesuit Province in the year 1983. With the appointment of Rt. Rev. Dr. Maxwell V. Noronha as the Bishop of Calicut, who took charge of the Diocese on September 8, 1980, the administration of the Diocese passed into the hands of the Diocesan clergy. His Holiness Pope John Paul II has created the Diocese of Kannur by bifurcating the Diocese of Calicut on December 09, 1998. The new Diocese consists of revenue districts of Kannur and Kasaragod. On May 19, 2002 Rt. Rev. Dr. Joseph Kalathiparambil was appointed as the Vth Bishop by the Holy See.