The Diocese of Balanga is a Latin Church diocese of the Catholic Church in the Philippines, established on March 17, 1975, by Pope Paul VI. The diocese has jurisdiction over the whole province of Bataan, with 38 parishes, 5 diocesan shrines, one minor basilica, chaplaincy, quasi-parish, national shrine and chapel, and 4 vicariates. The Cathedral-Shrine Parish of St. Joseph, Husband of Mary in Aguire Street, Poblacion, Balanga, serves as the seat of the diocese. It is part of the Ecclesiastical Province of San Fernando, Pampanga. The titular patron of the diocese is Saint Joseph, whose feast day falls on March 19. The city fiesta is celebrated on April 28.

As of October 2015, Bishop Ruperto Santos is the longest-serving living bishop of Balanga, having served for 13 years, 3 months, and 21 days (4,860 days) as the diocese's fourth bishop from April 1, 2010 (installed or assumed office on July 8, 2010 3 months and 7 days after being appointed to the position) to July 22, 2023.

The diocese became vacant when Santos became bishop of Antipolo covering Rizal province, and the city of Marikina in Metro Manila on July 22, 2023. Pope Francis then appointed Archbishop of San Fernando, Pampanga Florentino Lavarias as sede vacante apostolic administrator of the diocese while awaiting for the installation of Santos' successor as the diocese's bishop, returning Bataan temporarily to the jurisdiction of Archdiocese of San Fernando after 47 years and 8 months. On December 3, 2024, Pope Francis appointed Rev. Fr. Rufino Coronel Sescon, Jr., the current rector of Minor Basilica and National Shrine of Jesus Nazareno in Manila, to be the fifth Bishop of the diocese.

The Diocese of Balanga was established on March 17, 1975, from the territory of Archdiocese of San Fernando, Pampanga, by Pope Paul VI through the papal bull Quoniam Recte Universum. It comprises the entire civil province of Bataan, the smallest among the provinces of Central Luzon. The province is a peninsula jutting out to sea, with Manila Bay to the east, South China Sea to the west, and the province of Zambales to the north. Only 1 of the 15 priests of the diocese was a native of Bataan when Bishop Celso Guevarra was installed as the diocese's first bishop on November 8, 1975, eight months after the diocese was founded.

Before this, the region was divided into two parts: the Corregimiento of Mariveles and the Province of Pampanga. The towns of Mariveles, Bagac, Morong and Maragondon, Cavite, comprised the Corregimiento of Mariveles that was under the jurisdiction of the Recollect Order. The province of Pampanga included the towns of Orion, Pilar, Balanga, Abucay, Samal, Orani, Llana Hermosa and San Juan de Dinalupihan. The latter group was under the charge of the Dominican Order. Limay, the twelfth town of Bataan, was named only in 1917.

The topography of the province has made most of the inhabitants farmers or fishermen, with a sprinkling of merchants, factory workers and professionals. Recent years, however, have seen the development of manufacturing industries in the province, particularly the Free Zone in Mariveles which has brought an influx of workers from other provinces and improved living conditions of its own workers.

Historically, Bataan is most remembered, along with the island of Corregidor, as the main scene of action in the Philippines during the Second World War. These places are strategic in guarding the entrance to Manila Bay. The surrender of Filipino and American soldiers to overwhelming Japanese forces marked the Fall of Bataan in 1942. A war memorial, Dambana ng Kagitingan, now stands to honor the men who fought and died in that last stand.

During the 23-year tenure of Bishop Celso Guevarra, the diocese has continuously spread its branches far and wide. The number of parishes increased from 13 to 25. In each of these parishes, one can find many concerned, committed and generous lay leaders. Together with their parish priests, not only have they renovated and/or totally rebuilt their parish churches and convents but are actively responding to the never-ending demands of evangelization. The major diocesan commissions, which have been established, introduced new and various apostolates in the diocese and in the parishes.

The inspiring words and assuring presence of Honesto Ongtioco (now Bishop-emeritus of Cubao), who succeeded Bishop Celso, guided the young diocese as it celebrated its 25th anniversary and as it responded to the call of Pope John Paul II at the beginning of the third millennium, “Duc in Altum.” His kindness and charity allowed the various branches of the diocesan tree to grow in different directions in pursuit of his plan to convoke a Diocesan Pastoral Assembly. However, God has other and better plans both for Bishop Ongtioco and the diocese of Balanga. Bishop Ongtioco has just laid the foundation for the realization of his vision when he was installed to lead the new Diocese of Cubao in Quezon City on August 28, 2003.

During the tenure of Socrates Villegas (now Archbishop of Lingayen-Dagupan) as the diocese's third bishop in 2004, the annual celebration Mt. Samat Pilgrimage, held on November or December of the year, was started. It has the theme song titled "Bataan: Bayani at Banal" written by Villegas and music by Ryan Cayabyab.

In 2006, the Diocesan Schools of Bataan Educational Foundation, Inc. (DSOBEFI) was established to integrate Catholic schools in Bataan into the Diocese of Balanga.

On December 8, 2008, Clinica Diocesano de San Jose, the diocese's clinic, was founded which is a weekly medical and dental mission for the poor people of Bataan.

The diocese will celebrate its 50th anniversary in 2025. Its logo was unveiled on a celebration of the diocese's 48th canonical erection anniversary and Dedication of Saint Joseph Cathedral celebrated by its bishop Ruperto Santos (now bishop of Antipolo) and Archbishop of San Fernando, Pampanga Florentino Lavarias.

The miter symbolizes the pastoral authority of a bishop which he will be exercising the office of his position, represented by the Balanga Cathedral, within the diocese's jurisdiction which is the entire province of Bataan.

The coat of arms for the diocese's 50th anniversary also has a miter which symbolizes the bishop's pastoral authority which will be exercising within the province of Bataan and three-stemmed lilies which is the symbol of Saint Joseph.

The three red crosses symbolizes the Holy Trinity (God the Father, Jesus Christ, and the Holy Spirit), four small crosses inside a circle symbolizing the four former bishops of the diocese (Bishops Celso Guevarra, Honesto Ongtioco, Socrates Villegas, and Ruperto Santos), seven red and blue lines signifies the 7 sacraments of the Catholic Church, symbols of Dominican and Augustinian orders at the left and right side of the miter indicating that they are the missionaries who went to the province in order to teach the faith, with Dominicans built the churches of Abucay, Samal, Balanga, Orani, Pilar, Hermosa, and Orion, while the Augustinians built the Morong, Bagac, and Mariveles church. The number 50 and the years 1975 and 2025 represents the 50th anniversary of the diocese, with 1975 indicate the diocese's founding and 2025 for its 50th year. At the lower left is the letter "M" symbol (which is also used on the coat of arms of Bishop Ruperto Santos as Bishop of Balanga) symbolizing Virgin Mary serving as the diocese's and province's patroness under the name of Virgen Milagrosa de Orani and showing the devotion of the Bataan people to her. At the right is the map of Bataan from which the diocese has jurisdiction and authority with. At the bottom is a golden banner which has the text "Magtipon (Gather), Maglakbay (Travel), at Maghasik (Sow)" which are the theme for its 50th anniversary. "The daughters of kings, women of honor, are maidens in your courts. And standing beside you, glistening in your pure and golden glory, is the beautiful bride-to-be!" comes from Psalms 45, the word of God which is a guide for the celebration of 50 years of the diocese.

The Diocese of Balanga has 11 schools as of 2017, with 10 are operated by the diocese's Diocesan Schools of Bataan Educational Foundation, Inc. (DSOBEFI) under its superintendent Fr. Edgardo Sigua and assistant Fr. Alwin B. Bobis since June 2024.

• St. Catherine of Siena Academy, Samal (1960)
• St. John Academy, Dinalupihan (1960)
• Holy Rosary Parochial Institute, Orani (1963)
• St. Michael the Archangel Academy, Orion (1982)
• St. Nicholas Catholic School of Mariveles (1984)
• Our Lady of the Pillar Parochial School, Morong (1992)
• St. Peter of Verona Academy, Hermosa (1998)
• St. Joseph's College of Balanga City, Upper Tuyo Balanga City (2006)
• Blessed Regina Protmann Catholic School, Mt. View, Mariveles (2007)
• St. James Catholic School of Morong (2008)
• Virgen Milagrosa Del Rosario College Seminary (2015)
• Colegio Santa Catarina de Alexandria, Bagac (2017)

No.	Bishop	Period of Tenure	Coat of Arms
1	Celso Nogoy Guevarra	November 8, 1975 – June 18, 1998 (22 years, 222 days)
2	Honesto Flores Ongtioco	June 18, 1998 – August 28, 2003 (5 years, 71 days)
3	Socrates Buenaventura Villegas	May 3, 2004 – November 4, 2009 (5 years, 185 days) (installed July 3, 2004)
4	Ruperto Cruz Santos	April 1, 2010 – July 22, 2023 (13 years, 112 days ) (installed July 8, 2010)
5	Bishop-Elect Rufino Coronel Sescon Jr.	Appointed December 3, 2024

1. Antonio "Tony" S. Dumaual (died July 21, 2023 and funeral July 31, 2023) — August 28, 2003 (Honesto Flores Ongtioco)–July 3, 2004 (Socrates Buenaventura Villegas) (10 months, 5 days (310 days))
2. Victor de la Cruz Ocampo (later Bishop of Gumaca, Quezon), died March 16, 2023 and funeral March 27, 2023) — November 4, 2009 (Socrates Buenaventura Villegas)–July 8, 2010 (Ruperto Cruz Santos) (8 months, 4 days (246 days))
3. Florentino Galang Lavarias (Archbishop of San Fernando, Pampanga) — Ruperto Cruz Santos (July 22, 2023)–present

• Victor C. Ocampo, became Bishop of Gumaca on September 3, 2015.

• Catholic Church in the Philippines
• List of Catholic dioceses in the Philippines

• Media related to Roman Catholic Diocese of Balanga at Wikimedia Commons
• Roman Catholic Diocese of Balanga Official Website

14°40′45″N 120°32′24″E / 14.6792°N 120.5400°E / 14.6792; 120.5400