The Homer Tunnel is a road tunnel in the Fiordland region of the South Island of New Zealand, opened in 1954. New Zealand State Highway 94 passes through the tunnel, linking Milford Sound to Te Anau and Queenstown, by piercing the Main Divide at the Homer Saddle. It connects between the valley of the Eglinton and Hollyford Rivers to the east and that of the Cleddau to the west.
The tunnel is straight and was originally single-lane and gravel-surfaced. The tunnel walls remain unlined granite. The east portal end is at 945 m elevation; the tunnel runs 1270 m at approximately a 1:10 gradient down to the western portal. Until it was sealed and enlarged it was the longest gravel-surfaced tunnel in the World.Roof lighting was fitted and traffic lights reintroduced in 2004 to reduce capacity constraints and safety issues. Although the tunnel is large enough for a bus and a smaller vehicle to pass, meetings involving two coaches or campervans are problematic.