The Kohat Tunnel is a 1.9-kilometre-long highway tunnel under the Khigana Mountains between Kohat District and Dara Adam Khel Tehsil in the Khyber Pakhtunkhwa province of Pakistan. The tunnel carries northbound and southbound traffic along N-55 National Highway under the Kohat Pass. The tunnel is also referred to as the Pak-Japan Friendship Tunnel, as it was constructed with assistance from the Economic Cooperation Fund of Japan.