National Route 345 is a national highway of Japan connecting Chà «à Â-ku, Niigata and Yuza, Yamagata in Japan, with a total length of .
National Route 345 was established on 1 April 1975 as a route connecting Murakami, Niigata and Yuza, Yamagata.
On 19 June 2019, Route 345 was blocked by fallen debris in Murakami, Niigata because of the 2019 Yamagata earthquake.