Masuleh (Persian: ماسوله; ), also Romanized as Māsūleh, Masoleh and Masouleh, is a city in Sardar-e Jangal District of Fuman County, Gilan province, Iran. Historical names for the city include Māsalar and Khortāb. It was founded in the 10th century.

At the 2006 census, its population was 554 in 180 households. The following census in 2011 counted 568 people in 210 households. The latest census in 2016 showed a population of 393 people in 147 households.

Masuleh is approximately 60 km southwest of Rasht and 32 km west of Fuman. Its people are Talysh. The village is 1,050 meters above sea level in the Alborz (or Elburz) mountain range, near the southern coast of the Caspian Sea. The village itself has a difference in elevation of 100 meters.

Although it has been written that the community was established around 10 AD, the province of Gilan has a long history. The first village of Masuleh was established around 1006 AD, 6 km northwest of the current city, and it is called Old-Masuleh (Kohneh Masuleh in Persian). People moved from Old-Masuleh to the current city because of pestilence and attacks from neighbouring communities.

Masouheh-Rood-Khan is the river passing through the city, with a waterfall located just 200 meters away from the village. It's cut-off by snow during the winter months. Fog is the predominant weather feature of Masuleh.