Jedlnia-Letnisko [ˈjɛdlɲa lɛtˈniskɔ] is a town in Radom County, Masovian Voivodeship, in east-central Poland.

There are two walking trails and three bicycle trails leading through the Jedlnia Nature Reserve (86,42 ha), along the edge of the densely forested Kozienice Landscape Park.

One of the most notable natural monuments of the Jedlnia Nature Reserve is the Kościuszo Beech, an over 180-year-old European beech tree, named after Polish national hero Tadeusz Kościuszko.

During the German occupation of Poland (World War II), the occupiers operated a forced labour camp in Jedlnia-Letnisko.

Route 26 of the Radom city bus network operates selected trips from Radom via Rajec Poduchowny, Antoniówka, Wrzosów and Siczki to a terminus located at the railway station since 3 January 2022.