Hakalau Stream Bridge, Road bridge in Honomu, Hawaii, United States.

Hakalau Stream Bridge is a steel trestle viaduct running southeast to northwest over the Hakalau Stream, about 100 m before its mouth in Hakalau Bay. Its 236 m deck, roughly 55 m above the stream, is an 11.7 m wide steel plate-girder structure with a reinforced-concrete roadway carrying two lanes and side footpaths. The deck rests on two abutments and seven lattice steel masts up to over 50 m tall, set 22 m apart on concrete footings.

The Hilo Railroad Company built the steel trestle between 1910 and 1912 to carry sugar from east-coast plantations to Hilo; the steel parts came from Hamilton and Chambers in New York, and John Mason Young designed the structure. The 1946 tsunami damaged the line, and the bridge was widened for two lanes of Hawaii State Route 19 under engineer William R. Bartels, finished in 1953.

The bridge's name comes from the Hakalau Stream it crosses about 100 m above its mouth in Hakalau Bay. Its steel lattice towers were widened in the 1950s with near-identical outer sections on separate concrete footings, so each mast now stands on eight concrete bases. The former railway alignment survives as the roadbed of State Route 19.

The bridge carries two lanes of Hawaii State Route 19, part of the Hawaii Belt Road, about 20 km north of Hilo just north of Honomu. The deck sits roughly 55 m above the Hakalau Stream, about 100 m before its mouth in Hakalau Bay. Approach cuts of up to 10 m deep on both sides keep the grade gentle.

The bridge deck sits about 55 metres above the Hakalau Stream, though literature gives figures between 52.1 and 57.9 metres. To avoid steep gradients on the railway, cuttings roughly 250 metres long and up to 10 metres deep were dug on both sides of the bridge.