Princess Margaret Bridge, Truss bridge in Fredericton, Canada

Princess Margaret Bridge is a two-lane steel truss highway bridge over the Saint John River at Fredericton, New Brunswick. It is 1,097 m long and gives 25 m of navigation clearance at its centre. It carries Route 8, the main Fredericton–Miramichi highway, and is named after Princess Margaret, Countess of Snowdon, sister of Queen Elizabeth II.

The bridge opened in 1959 as part of a highway bypass project and took its name from Princess Margaret, sister of Queen Elizabeth II. It was built during an era when new infrastructure supported the city's expansion.

The bridge is a daily crossing for people in Fredericton, woven into the rhythm of their regular journeys across the river. Over decades, it has become a familiar landmark that helps residents navigate their city.

The bridge carries two narrow lanes with a posted speed limit of 70 km/h, and its deck is prone to severe icing in winter. At the southern end, northbound drivers face a sharp incline and a 30-degree turning radius to reach the span, and the Forest Hill Road ramps have very tight curves. After crossing northbound, travellers continuing on Route 8 must exit immediately on a ramp and pass back under the roadway toward Marysville.

In early May 2009 a 10-kilogram chunk of concrete fell from the bridge onto the roadway below, narrowly missing a passing motorist's vehicle; a major refurbishment followed. The deck is also prone to severe icing in winter, and the posted speed limit is 70 km/h.