La Union in the context of "Ilocos Sur"

The Ilocos Region (Ilocano: Rehion/Deppaar ti Ilocos; Pangasinan: Rehiyon na Ilocos; Tagalog: Rehiyon ng Ilocos), designated as Region I, is an administrative region of the Philippines. Located in the northwestern section of Luzon, it is bordered by the Cordillera Administrative Region to the east, the Cagayan Valley to the northeast and southeast, Central Luzon to the south, and the South China Sea to the west. The region comprises four provinces: Ilocos Norte, Ilocos Sur, La Union, and Pangasinan, along with one independent-component city, Dagupan City. The regional center is the city of San Fernando in La Union, which serves as the administrative hub of the region. The largest settlement in terms of population is San Carlos City in Pangasinan.

The 2020 Philippine Statistics Authority census reported that the ethnolinguistic group composition of the region is predominantly made up of Ilocanos (58.3%), followed by Pangasinans (29.7%), Tagalogs (4.1%), and various Cordilleran (Igorot) indigenous groups.

Iloco (also Ilóko, Ilúko, Ilocáno or Ilokáno; /iːloʊˈkɑːnoʊ/; Iloco: Pagsasaó nga Ilóko) is an Austronesian language primarily spoken in the Philippines by the Ilocano people. It is one of the eight major languages of the Philippines with about 11 million speakers and ranks as the third most widely spoken native language. Iloco serves as a regional lingua franca and second language among Filipinos in Northern Luzon, particularly among the Cordilleran (Igorot) ethnolinguistic groups, as well as in parts of Cagayan Valley and some areas of Central Luzon.

As an Austronesian language, Iloco or Ilocano shares linguistic ties with other Philippine languages and is related to languages such as Indonesian, Malay, Tetum, Chamorro, Fijian, Māori, Hawaiian, Samoan, Tahitian, Paiwan, and Malagasy. It is closely related to other Northern Luzon languages and exhibits a degree of mutual intelligibility with Balangao language and certain eastern dialects of Bontoc language. Iloco is also spoken outside of Luzon, including in Mindoro, Palawan, Mindanao, and internationally in Canada, Hawaii and California in the United States, owing to the extensive Ilocano diaspora in the 19th and 20th centuries. About 85% of the Filipinos in Hawaii are Ilocano and the largest Asian ancestry group in Hawaii. In 2012, it was officially recognized as the provincial language of La Union, underscoring its cultural and linguistic significance.

Pangasinan (Pangasinense) is an Austronesian language, and one of the eight major languages of the Philippines. It is the primary and predominant language of the entire province of Pangasinan and northern Tarlac, on the northern part of Luzon's central plains geographic region, most of whom belong to the Pangasinan ethnic group. Pangasinan is also spoken in southwestern La Union, as well as in the municipalities of Benguet, Nueva Vizcaya, Nueva Ecija, and Zambales that border Pangasinan. A few Aeta groups and most Sambal in Central Luzon's northern part also understand and even speak Pangasinan as well.

San Fernando, officially the City of San Fernando (Ilocano: Siudad ti San Fernando; Filipino: Lungsod ng San Fernando), is a component city and the capital of the province of La Union, Philippines. It serves as the regional and administrative center of the Ilocos Region. The city also functions as a hub for trade and commerce in northern Luzon and as a center for the culture and heritage of Ilocandia. According to the 2024 census, it has a population of 124,809 people with 77,490 registered voters as of 2025.

The City of San Fernando is a coastal city facing the South China Sea to the west and bordered by the Cordillera Central mountain range to the east. It consists of 59 barangays and has a total land area of 105.26 square kilometers. The city's majority ethnolinguistic group are the Ilocano people who speak Iloco language, as the city has historically been an Ilocano stronghold. It is one of two capital cities in the Philippines named San Fernando, the other being San Fernando, Pampanga.

The Pangasinan people (Pangasinan: Totoon Pangasinan), also known as Pangasinense, are an ethnolinguistic group native to the Philippines. Numbering 1,823,865 in 2010, they are the tenth largest ethnolinguistic group in the country. In the 2020 census Pangasinan speaking households made up roughly 1.3% of Philippine households. They live mainly in their native province of Pangasinan and the adjacent provinces of La Union and Tarlac, as well as Benguet, Nueva Ecija, Zambales, and Nueva Vizcaya. Smaller groups are found elsewhere in the Philippines and worldwide in the Filipino diaspora.