The Diocese of Kalookan is a diocese of the Latin Church of the Catholic Church in Metro Manila, Philippines which comprises Malabon, Navotas, and the southern portion of Caloocan.

The Diocese was created by Pope John Paul II on June 28, 2003 through his apostolic letter Quoniam Quaelibet. The diocese was canonically erected on August 22, 2003, with the installation of its first bishop, Deogracias S. Iñiguez, then Bishop of Iba, Zambales. Upon Iñiguez's resignation on January 25, 2013, Antipolo Auxiliary Bishop Francisco M. De Leon was named Apostolic Administrator of the diocese. On October 14, 2015, Pope Francis named Pablo Virgilio S. David, auxiliary bishop of Archdiocese of San Fernando in Pampanga, as the second bishop of Kalookan and installed on January 2, 2016.

On October 6, 2024, Pope Francis appointed Bishop David a cardinal effective on December 7, 2024. He is the tenth Filipino to join the College of Cardinals, the third Filipino made a cardinal by Pope Francis, the first cardinal from Diocese of Kalookan, and the first cardinal from any diocese in the Philippines. On October 23, the Synod of Bishops elected David a member of the Ordinary Council of the General Secretariat of the Synod.

As of 2021, there are approximately 1,330,840 people in the diocese, with ~89% of them (~1,184,000) being baptized Catholics, and there are 76 priests (40 diocesan and 36 religious) serving 31 parishes. The average number of baptisms in a year between the years 2003-05 was 680. The two prominent Christian religions in the diocese next to Catholicism are the Philippine Independent Church (IFI, Aglipayan) and Iglesia ni Cristo (Church of Christ).

Bishop			Period in Office	Coat of Arms
1.		Deogracias S. Iñiguez, Jr.	August 22, 2003 – January 25, 2015 (11 years, 156 days)
2.		Pablo Virgilio S. David	January 2, 2016 – present (9 years, 8 days)

• Catholic Church in the Philippines

• Media related to Roman Catholic Diocese of Kalookan at Wikimedia Commons
• Dioecesis Kalookana Catholic-Hierarchy.org