The Hokkaidō Shinkansen (北海道新幹線?) is a high-speed rail line currently under construction between Aomori (Honshu) and Hokkaido through the Seikan Tunnel. Construction started in May 2005, and the initial Shin-Aomori to Shin-Hakodate section is projected to open in 2015. On June 30th, 2012, the government approved construction of the line to Sapporo by fiscal 2035.[1] The line will be operated by the Hokkaido Railway Company (JR Hokkaido).[2]

Tōhoku and Hokkaido Shinkansen services are hoped to be operated at speeds of up to 360 km/h. The proposed journey time from Tokyo to Sapporo is advertised locally as 3 hours, 57 minutes.

At the present time the Seikan Tunnel can only carry narrow-gauge (1,067 mm) traffic (Kaikyō Line), but it will be upgraded to dual gauge, with both standard and narrow-gauge tracks.

In the early 1970s, two other Shinkansen routes were proposed for Hokkaido: Sapporo - Asahikawa (Hokkaido Shinkansen extension) and Oshamambe - Muroran – Sapporo (Hokkaido South Route). There were also further, unofficial plans to connect to Abashiri, Kushiro and Wakkanai. These plans have been indefinitely shelved.