The Diocese of Alaminos (Latin: Dioecesis Alaminensis) is a Latin Church ecclesiastical jurisdiction or diocese of the Catholic Church in the Philippines.

The diocese was erected on January 12, 1985, and comprises 14 municipalities in the western part of the province of Pangasinan. The diocese has experience no jurisdictional changes, and is a suffragan of the Archdiocese of Lingayen-Dagupan.

On the Feast of St. Thomas Aquinas, January 28, 2024, Pope Francis appointed Napoleon Balili Sipalay, Jr., of the Order of Preachers, then-vice rector of the UST Central Seminary, to be the new bishop of Alaminos. His episcopal ordination by ordaining Archbishop Socrates Villegas with Bishop Jacinto Agcaoili Jose and Auxiliary Bishop Fidelis Bautista Layog as co-consecrators was held on March 18 at Manaoag Church. His solemn installation and canonical possession as the fourth bishop of the diocese was held on March 19, 2024 at the Alaminos Cathedral.

Ordinaries

No	Name	In office	Coat of arms
1.	Jesus Cabrera	April 22, 1985 – July 1, 2007
2.	Marlo Peralta	July 1, 2007 – December 30, 2013
3.	Ricardo Baccay	February 20, 2016 – January 14, 2020
4.	Napoleon Sipalay	March 19, 2024 – present

See also

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