Lavasan (Persian: لواسان)[a] is a city in, and the capital of, Lavasanat District of Shemiranat County, Tehran province, Iran.

It refers to Mount Damavand that is located in the middle Alborz Range in the east of Lavasanat District.

Until the construction of Road 59 (Chalous Road) and other routes to the north of Iran, Great Lavasan was a thriving city on a trade path between Tehran and the north of Iran, with several prominent families owning and managing the Lar Karvansara in the (now nationalized) Lar National Park, and who were active in the trading of rice and production of honey, among other products; hence the name "Great Lavasan".

In the early 1900s Great Lavasan was home to several affluent families and traders with many unique and thriving orchards.

Under Mohammad Reza Pahlavi, in the 1960s, a hydroelectric dam was built in the southeast of the village which is nowadays one of the water supplies of Tehran.