National Route 46 (国道46号, Kokudō yonjūrokugō) is a national highway of Japan that connects the capital cities of Iwate Prefecture and Akita Prefecture, Morioka and Akita.

National Route 46 is one of the primary east-west highways in the prefectures of Akita and Iwate and the main route between the cities of Morioka in the Iwate Prefecture's interior plains and the city of Akita on the Sea of Japan coast.

The highway's eastern terminus lies at a junction with National Route 4 southeast of central Morioka.

A section of the highway is built to expressway standards in the city of Semboku.

The highway was completed in December 1975, but the road over the Ōu Mountains was deemed to be insufficient.