Lidlidda, officially the Municipality of Lidlidda (Ilocano: Ili ti Lidlidda; Filipino: Bayan ng Lidlidda), is a 5th class municipality in the province of Ilocos Sur, Philippines. According to the 2015 census, it has a population of 4,647 people.
It is home to the Lidlidda Protected Landscape, a protected area situated in the municipality’s watershed.
The Lidlidda Protected Landscape, also known as the Lidlidda–Banayoyo Protected Landscape, is a protected area of natural springs and surrounding mountain forests in Ilocos Sur on the island of Luzon in the Philippines. It is an important watershed providing the agricultural and household water requirements of the communities in the municipalities of Lidlidda and Banayoyo.
It was established in 1936 as the Lidlidda Watershed Forest Reserve through Proclamation No. 79 signed by President Manuel Luis Quezon with an initial area of 1,228 hectares. In 2000, under the National Integrated Protected Areas System, it was redesignated as a protected landscape area covering its present size of 1,157.44 hectares.