The Ilocos Region (Ilokano: Rehion/Deppaar ti Ilocos; Pangasinan: Sagor na Baybay na Luzon; Tagalog: Rehiyon ng Ilocos) is an administrative region of the Philippines, designated as Region I, occupying the northwestern section of Luzon. It is bordered by the Cordillera Administrative Region to the east, the Cagayan Valley to the northeast and southeast, and the Central Luzon to the south. To the west lies the South China Sea.

The region comprises four provinces: Ilocos Norte, Ilocos Sur, La Union and Pangasinan. Its regional center is San Fernando, La Union. The 2000 Census reported that the major languages spoken in the region are Ilocano at 66.36% of the total population at that time, Pangasinan with 27.05%, and Tagalog with 3.21%.