National Route 129 is a national highway of Japan connecting Hiratsuka and Sagamihara in Kanagawa Prefecture in the Kantō region of Japan.

It has a total length of 31.7 km (19.7 mi).

The route runs in a north to south direction and has junctions with some major expressways.

[2] Route 129 was originally designated on 18 May 1953 from Yokohama to Chiba as a loop around Tokyo.

The entire route is in Kanagawa Prefecture.