The Aterazawa Line (左沢線, Aterazawa-sen) is a railway line in Yamagata Prefecture, Japan, operated by East Japan Railway Company (JR East).

All trains run through to and from Yamagata Station.

The line was opened to Uzen-Nagasaki in 1921, and extended to Aterazawa the following year.

CTC signalling was commissioned on the line in 1982.

The Sanzan Electric Railway operated an 11 km line from Uzen-Takamatsu Station to Mazawa, electrified at 600 V DC, between 1926 and 1974.