Kanmon Tunnel may refer to:
Kanmon Railway Tunnel, undersea rail tunnel connecting the islands of Honshu and Kyushu Kanmon Roadway Tunnel, undersea road tunnel connecting Shimonoseki, Yamaguchi and Moji-ku, Kitakyūshū , undersea pedestrian tunnel underneath the Kanmon Roadway Tunnel Shin-Kanmon Tunnel, undersea rail tunnel connecting Shin-Shimonoseki Station and Kokura Station