Hart's Weir Footbridge is a single-span concrete footbridge across the River Thames in Oxfordshire, England. Locally, it is also known as Rainbow Bridge, due to its rainbow-arc appearance as seen from the horizon. It is situated on the reach above Northmoor Lock, the nearest village being Appleton, Oxfordshire to the east.

Hart's Weir Footbridge
Coordinates	51°42′23″N 1°23′36″W / 51.706487°N 1.393298°W / 51.706487; -1.393298
Carries	Footpath
Crosses	River Thames
Locale	Appleton, Oxfordshire
Characteristics
Material	Concrete
Height	10 feet 9 inches (3.28 m)
No. of spans	1
History
Opened	1879
Location

The bridge was built in 1879 on the site of a weir that was removed a year later. Then known as Hart's Weir, it had previously been Ridge's, Langley's, Cock's, Rudge's, and Butler's Weir.^[1] Sixteen years later Northmoor Lock was built downstream.