The Sardinian warbler has a distribution restricted to western Europe, where it is especially Mediterranean, occurs in northwest Africa, and also has populations in the Near East (Keller et al., 2020; BirdLife International, 2024). In Spain, it is distributed in a fragmented manner, with higher abundances in the Ebro Depression, the northern plateau, and the Central System, as well as along the Mediterranean coast from Cabo de la Nao to Gibraltar (Calleja and Pérez-Granados in SEO/BirdLife, 2022). It occurs in the Balearic Islands and in the Canary Islands as the subspecies orbitalis, endemic to the Macaronesian region (Trujillo in Lorenzo, 2007).

In the Community of Madrid, it appears in the central and northeastern areas, with its main nucleus in the grasslands of the mountain foothills, and scattered populations in the southern half. It prefers esparto grasslands and kermes oak scrubs in the south, and very open juniper groves in the northern half (Díaz et al., 1994).

In the national park, the highest abundances are found along the eastern portion of Cuerda Larga and around the Morcuera pass, in slope and grassland areas with some shrub substrate of broom and other shrubs in clearings, edges, and borders with forest stands. It is also located in high-altitude grassland areas with shrubby substrate in the northeastern end of the park, around Navafría pass and Reajo Alto.