National Route 105 is a national highway of Japan that traverses the prefecture of Akita in a southwest–northeast routing. It connects the city of Kitaakita in north-central Akita Prefecture and Yurihonjō on the prefecture's southwestern coast. It has a total length of 170.0 kilometers (105.6 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.