Dilasag separated from Casiguran
History
The name "Dilasag" can be divided into two syllables. The prefix "Di" in the Native Language means "abundance", added to the word "lasag" which means "meat". The coined word "Dilasag", however, does not only mean abundance of meat in the place, but also refers to the over sufficient supply of forest products, marine products and minerals.
In early 1924, a group of Ilocano settlers with a number of Kapampangans & Pangasinenses from the Province of Tarlac arrived in Casiguran, which is now the adjacent Town of Dilasag, which were then part of Nueva Vizcaya. Finding the natives unfriendly to them, these new settlers ventured to move along the coastline going north and settled finally to what is now called Dilasag.  The place was considered habitable, because the Native Dumagats in the place were friendly. Later, more families came, making the place a community. This community was soon recognized by the Local Chief Executive of Casiguran, formerly a municipality of the Province of Quezon. It was declared a sitio of barangay Culat and eventually a barrio of Casiguran in consideration of its rapid progress and development. In 1959, Quezon 1st District Representative Manuel Enverga introduced House Bill No. 2863 in the House of Representatives, resulting to the approval of Republic Act No. 2452 on June 21, 1959, making Dilasag a municipal district, separating it from Casiguran. It was then part of the province of Quezon under the sub-province of Aurora until the latter became a province of its own in 1979.