The Gananoque River Bridge is a railway bridge across the Gananoque River in the municipality of Leeds and the Thousand Islands, United Counties of Leeds and Grenville in eastern Ontario, Canada, located between Montreal and Toronto at mile 155.9 in the Canadian National Railway Kingston subdivision.

It consists of four identical spans carrying single track supported on common piers and abutments and was built in 1902–1903 according to Grand Trunk Railroad specifications of 1900.

The 132-pound (60 kg) type rails are supported by 250-by-250-millimetre (9.8 in × 9.8 in) timber railway ties in section with a 356-millimetre (14 in) spacing.

A 1991 engineering study showed "no major structural deficiency of the bridge superstructure in terms of excessive stresses or deflections under normal traffic conditions".

Tests indicated that the static strength of the bridge sufficient to allow trains running at speeds not exceeding 96 km/h (60 mph).