The Iida Line (飯田線, Iida-sen) is a Japanese railway line connecting Toyohashi Station in Toyohashi, Aichi with Tatsuno Station in Tatsuno, Nagano, operated by Central Japan Railway Company (JR Central).

The line has an unusually high number of so-called Hikyō stations, or hikyo-eki, which have since lost their nearby communities due to depopulation.

[1] The phrase was coined in 1999 by Takanobu Ushiyama and friends, for railroad stations that are isolated and little used.

[1] Traveling the entire length of the 195.7 km (121.6 mi) line by local trains takes six hours.

In 1955, the overhead line voltage of the Tatsuno to Tenryukyo section was increased to 1,500 V DC.