The E351 series (E351系) was a tilting electric multiple unit (EMU) train type operated by East Japan Railway Company (JR East) on Chuo Main Line Super Azusa limited express services in Japan from 1993 to 2018.

Built jointly by Hitachi and Nippon Sharyo,[1] the tilting E351 series trains were intended to replace the aging 183 series EMUs used on Azusa Limited express services operating between Shinjuku in Tokyo and Matsumoto, and to increase speeds on the highly curved Chūō Main Line.

[2] At the time of withdrawal in 2018, the E351 series trains were used on the following services: Other services previously operated by the series include: The fleet consisted of five four-car sets (S21–S25) and five eight-car sets (S1–S5), formed as shown below, with car 1 (car 5) at the Shinjuku or Tokyo end.

[5] On 12 October 1997, the down Super Azusa 13 service from Shinjuku to Matsumoto (formed of sets S3+S23) was involved in a collision with a 201 series local train that had overrun a red signal while passing through Ōtsuki Station.

[7] After their withdrawal, the trains were transferred to Nagano General Rolling Stock Center for scrapping.