Manjil (Persian: منجيل)[a] is a city in the Central District of Rudbar County, Gilan province, Iran.

There are numerous archaeological site excavations (mostly illegal) in the Manjil area because of its rich cultural history.

Some of these sites are related to the Ismaili era, i.e., Hassan Sabbah movement based in Alamoot forte (one may find artifacts from the 3rd-2nd millennia BC in some households).

General Dunsterville's private diaries and notes, including those kept during his command of the Dunsterforce Mission to North Persia and Baku, 1918 were transcribed from the original by General Dunsterville's great-granddaughter, and are co-located on the Great War Primary Documents Archive.

Since 1960 it has been the site of the Manjil Dam that significantly contributes to Gilan's agriculture, such as its olive groves, while generating electric power.