The New Westminster Bridge (also known as the New Westminster Rail Bridge (NWRB) or the Fraser River Swing Bridge) is a swing bridge that crosses the Fraser River and connects New Westminster with Surrey, British Columbia, Canada.

The bridge is owned by the Government of Canada. Since 1992, the Canadian National Railway (CNR) has operated and maintained the bridge. The Southern Railway of British Columbia (SRY), Canadian Pacific Kansas City (CPKC), and BNSF Railway have track usage rights. Passenger rail service over the bridge is offered by Amtrak's Cascades (with service to Portland and Seattle), Via Rail's The Canadian (with service to Toronto), and Rocky Mountaineer.

Construction of the New Westminster Bridge began in August 1902, and the new bridge was formally opened on July 23, 1904 by the Lieutenant governor of British Columbia. It was originally built with two decks; the lower deck was used for rail traffic while the upper deck was used for automobile traffic.

Before the New Westminster Bridge was built, crossing the river required boarding the K de K or Surrey ferry, which docked at the present day neighbourhood of South Westminster (formerly the historic community of Brownsville) located in the city of Surrey.

The toll for the upper bridge was 25 cents and created quite an uproar for farmers who found out quickly that by taking their livestock across on foot would cost them a quarter a head but if they put them in a truck it cost a quarter for the whole load.

The bridge was the preferred method of transport across the Fraser until the opening of the Pattullo Bridge in 1937. The upper deck was removed and the bridge was converted exclusively for rail use.

By 2003, the bridge handled 46 train crossings per day (out of a rated daily capacity of 59 trains), and it was identified as a first-priority rail infrastructure project in Greater Vancouver. Three improvement scenarios were studied in 2004. The first scenario kept status quo operations between rail carriers but replaced the bridge with a new CAD$110 million, 850-metre long (2,790 ft), single-track vertical lift bridge replacement that supports higher speeds, has a higher 11.7-metre clearance (38 ft) when closed, and is expandable to a double-track bridge. The second scenario maintained status quo operations but replaced the bridge with a new CAD$420 million, 7.5-kilometre long (4.7 mi), single-track tunnel (immersed tube below the Fraser River channel) to replace the existing bridge. The third scenario implemented coordinated rail operations between rail carriers but retained the existing bridge.

The study recommended that coordinated rail operations be undertaken, because while the study was in progress, CNR and CPKC predecessor Canadian Pacific Railway (CPR) began some coordinated operations to address growing trade volumes with Asia. These new operations helped to reduce traffic pressures at the bridge. In January 2006, CNR and CPR expanded the scope of their coordinated rail operations. Also, CNR entered an agreement with BNSF to gain operational, dispatching and maintenance control of BNSF track from the bridge northward throughout the Burrard Peninsula in exchange for CN assets in Illinois and Tennessee, such as similar control of interlockers in Chicago, Illinois and Memphis, Tennessee and other trackage rights. Because of this agreement, CNR gained greater control of its main line corridor from Vancouver's North Shore, its Second Narrows Rail Bridge across Burrard Inlet, and Thornton Tunnel by connecting them through the BNSF track to the New Westminster Bridge and CNR's main line track south of the Fraser River. By 2014, the implementation of coordinated rail operations was considered a success in preserving available rail capacity at the bridge, at least on a short-term (20-year) basis.

In 2010, as part of investigations to replace the original Pattullo Bridge road crossing adjacent to the New Westminster Bridge, Transport Canada studied two possible options to replace the rail crossing: a double-track, single-deck bridge at the same elevation for CAD$360 million, and a double-deck bridge for CAD$470 million. CNR advocated its own option, which was a triple-track, single-deck vertical-lift bridge at the same elevation for CAD$600 million. The upstream and middle bridge tracks would connect the CNR-controlled BNSF main line tracks north of the river to the CNR main line tracks south of the river, while the downstream bridge track would be accessible from all 5 approaches, like the lone track on the current bridge.

As of 2004, the speed limit for trains was 11 miles per hour (18 kilometres per hour), which had been increased from 8 mph (13 km/h).

The bridge is a heavily used single-track railway that supports only low train speeds and is swung open for marine traffic for a significant portion of each day. Because of this situation, studies have been conducted to relocate the northern terminus of Amtrak's Cascades passenger train service from Pacific Central Station in downtown Vancouver southeast by 21 kilometres (13 mi) to Surrey. The proposed new terminus at the Skytrain rapid transit system's Scott Road Station is about 900 metres (3,000 ft) from the bridge. The location would allow additional round trips from Seattle, Washington to be added by avoiding the need to cross the Fraser River.

In the early 2020s, CNR completed seismic upgrades to the bridge.

The bridge opens for marine traffic about 20 times each day. It takes about 7 minutes for the bridge to swing open or closed.

On December 26, 1975, the bridge was damaged when a gale wind pushed a drifting log barge into the structure, ripping out the 120-metre main span (380 ft). The bridge was repaired and returned to service in late April 1976. The relatively quick fix was helped by modifying a recently completed design for a span that was just 1.5 metres (5 ft) shorter, created by the Howard, Needles, Tammen & Bergendoff design firm of Kansas City, Missouri for the Rulo Rail Bridge over the Missouri River in Rulo, Nebraska.

On May 29, 1982, a significant fire broke out on the New Westminster Bridge. The fire put the bridge out of service for almost a month. The bridge reopened on June 23, 1982.

On November 28, 1987, a barge struck the bridge. The resulting legal action of Canadian National Railway Co. v. Norsk Pacific Steamship Co. became a leading Supreme Court of Canada decision.

• List of crossings of the Fraser River
• List of bridges in Canada

• Media related to New Westminster Bridge at Wikimedia Commons
• Archival photos of the bridge from the New Westminster Public Library