The E127 series (E127系) is a DC electric multiple unit (EMU) train type operated on local services by East Japan Railway Company in Japan since 1995, and also by the third-sector railway operator Echigo Tokimeki Railway since March 2015 as the ET127 series. The design is derived from the 209 series commuter EMU.

The Echigo TOKImeki Railway Company (ETR) is a Japanese third-sector railway operating company established in 2010 to operate passenger railway services on the sections of the JR East Shinetsu Main Line and JR West Hokuriku Main Line within Niigata Prefecture when they were separated from the respective JR Group operators in March 2015, coinciding with the opening of the Hokuriku Shinkansen extension from Nagano to Kanazawa. The main shareholders of the company are Niigata Prefecture, the city of Joetsu, the city of Itoigawa, and the city of Myoko.