[4] The name Agno was derived from a species of swamp tree called “Agno Casto”, a chaste tree used for medicinal concoctions to relieve pain and illness, that grew abundantly in the locality.

1004 dated November 30, 1903, of the Philippine Commission, the northern part of Zambales including Agno was annexed to the Province of Pangasinan.

Poverty incidence of Agno Source: Philippine Statistics Authority[12][13][14][15][16][17][18][19] The town's main livelihood is fishing and agriculture, although a number of her sons and daughters work as doctors, physical therapist, nurses, engineers, computer programmers and accountants in numerous countries around the globe.

On top of that, the town produces successful teachers, policemen and policewomen, and lawyers.

Agno, belonging to the first congressional district of the province of Pangasinan, is governed by a mayor designated as its local chief executive and by a municipal council as its legislative body in accordance with the Local Government Code.