Talysh Mountains (Azerbaijani: Talış dağları, Талыш дағлары, تالش داغلارى; Persian: کوههای تالش, Kuhhâye Tâleš) is a mountain range in far southeastern Azerbaijan and far northwestern Iran within Ardabil Province and Gilian Province.
They are a northwestern subrange of the Alborz / Elburz Mountains that run along the southern Caspian Sea on the Iranian Plateau.
The Talysh Mountains extend southeastward from the Lankaran Lowland in southeastern Azerbaijan to the lower part of the Sefid Rud (White River) in northwestern Iran.
A few peaks rise above 10,000 ft (3,000 m).
Geologically, the Talish Mountain Range is made mainly of the Late Cretaceous volcano-sedimentary deposits with a strip of Paleozoic rocks and a band of Triassic and Jurassic rocks in the southern parts, both in a north-west-southeast direction.
The maximum annual precipitation in the Talysh Mountains is between 1,600 mm to 1,800 mm, which along the Lankaran Lowland is the highest precipitation in both Azerbaijan and Iran. The humid semi-subtropical coastal lowlands along the Caspian Sea, including the Lankaran Lowland, lie at the eastern base of the mountains.
The Caspian Hyrcanian mixed forests ecoregion, with habitats of lush lowland and montane forests (subtropical and temperate rainforests) cover the Talysh Mountains.