Kai Tak Tunnel , formerly known as the Airport Tunnel is a tunnel in New Kowloon, Hong Kong, which connects the Kowloon Bay and To Kwa Wan areas by going beneath the . It is part of . It provides a quick link between the two ends of the tunnel, as before the construction of the tunnel vehicles have to detour through Kowloon City to reach the other end.
Construction of the tunnel started in 1976, but because of the difficulties in digging under the airport runway, it was not complete until 1982. It was known as Kowloon Bay Tunnel at the time of its opening, and it was also the first tunnel in Hong Kong to be toll-free.
With Kai Tak Airport's shutdown in 1998, the Airport Tunnel no longer fulfilled its name. The Hong Kong Government announced on March 2, 2006 that the tunnel be renamed to Kai Tak Tunnel, effective from May 4, 2006, after several years of consultation with groups including the Kowloon City District .