Manilla railway underbridges, Heritage railway bridges in Manilla, New South Wales, Australia.

The Manilla railway underbridges are two structures spanning Borah Creek and Oakey Creek, each built with wooden Howe truss frames and open deck designs. The railway track sits directly on horizontal beams supported by timber trusses underneath, creating a straightforward system for carrying trains across the creeks.

The structures were built between 1907 and 1908 by the New South Wales Government Railways as part of the new rail line connecting Tamworth and Barraba. They represented early infrastructure development in linking inland areas with the growing railway network.

Both bridges were added to the New South Wales State Heritage Register on 2 April 1999, and the Borah Creek bridge had already been listed on the now-defunct Register of the National Estate on 18 April 1989. The register assesses them as historically, scientifically, archaeologically and socially rare. Timber was chosen because of the remote location and branch-line cost limits.

The bridges are visible from local roads that pass underneath the railway line, allowing good views of the structures from ground level. The best approach is to drive from Manilla town, as both sites are located a short distance outside the town centre.

Both bridges use the same 9.8–10.7 m deck Howe truss type, introduced in 1902 and dropped in 1908, the year these two were finished. Comparable survivors stand over the Murrumbidgee River at Gundagai and at the neighbouring creek, 17 km away. The Borah Creek trusses have five bays with timber compression diagonals and steel tie rods.