Quirino, officially the Province of Quirino, is a landlocked province in the Philippines located in the Cagayan Valley region in Luzon. Its capital is Cabarroguis. It is named after Elpidio Quirino, the sixth President of the Philippines.
The province borders Aurora to the southeast, Nueva Vizcaya to the west, and Isabela to the north. Quirino used to be part of the province of Nueva Vizcaya, until it was separated in 1966.
Long before its formal creation as an independent province, Quirino was the forest region of the province of Nueva Vizcaya, inhabited by tribal groups known as the Negritos. They roamed the hinterlands and built their huts at the heart of the jungle. Aside from the Negritos, the area was also inhabited by Ilongot people, who were feared for their headhunting raids against enemy tribes and Spanish-controlled settlements. Throughout the period of Spanish colonization, the province was one of the few remaining unconquered areas in the Philippines due to its remoteness, having only seen a Spanish military expedition in 1848 and the brief presence of Spanish missionaries in 1891. During the American period, the territory of Quirino was administered by the province of Isabela before Congressman Leon Cabarroguis of Nueva Vizcaya pushed for its return to Nueva Vizcaya by authoring Republic Act No. 236, which was signed into law in 1948.
On June 18, 1966, Republic Act No. 4734 was enacted, constituting the municipalities of Diffun, Saguday, Aglipay, and Maddela, all from Nueva Vizcaya province, into a new sub-province to be known as "Quirino", named after the late Philippine President Elpidio Quirino.
On June 21, 1969, Republic Act No. 5554 was enacted, amending RA 4734, and creating the municipality of Cabarroguis (now the provincial capital town), which was taken from portions of Diffun, Saguday, and Aglipay.
Republic Act No. 6394, authored by then-Congressman Leonardo B. Perez (Nueva Vizcaya–Lone), was passed on September 10, 1971, further amending RA 5554 and separating the sub-province of Quirino from its mother province, Nueva Vizcaya, constituting it into a regular province.
The province of Quirino was formally established on February 10, 1972, upon the assumption to office of the first elected provincial and municipal officials headed by Dionisio Sarandi as Provincial Governor.
On February 25, 1983, Batas Pambansa Blg. 345 was enacted, creating within Quirino the municipality of Nagtipunan, a division of the municipality of Maddela.