National Route 48 is a national highway of Japan that connects the capital cities of Miyagi Prefecture and Yamagata Prefecture, Sendai and Yamagata. It has a total length of 75.0 kilometers (46.6 mi).

Japan has a nationwide system of national highways distinct from the expressways. The Ministry of Land, Infrastructure, Transport and Tourism and other government agencies administer the national highways. Beginning in 1952, Japan classified these as Class 1 or Class 2. Class 1 highways had one- or two-digit numbers, while Class 2 highways had three-digit numbers. For example, routes 1 and 57 were Class 1 highways while 507 was a Class 2 highway.