Alborz ( listen (help·info) Persian: البرز), also written as Alburz, Elburz or Elborz, is a mountain range in northern Iran stretching from the borders of Azerbaijan and Armenia in the northwest to the southern end of the Caspian Sea, and ending in the east at the borders of Turkmenistan and Afghanistan. The highest mountain in West Asia, Mount Damavand, Amol, Mazandaran is located in the range.

The Alborz mountain range forms a barrier between the south Caspian and the Qazvin-Tehran plateau. It is only 60–130 km wide and consists of sedimentary series dating from Upper Devonian to Oligocene, prevalently Jurassic limestone over a granite core. Its higher elevations, in the Elburz Range forest steppe ecoregion, are arid with few trees, but its northern slopes, in the Caspian Hyrcanian mixed forests ecoregion, are lush and forested.