Southwark  Bridge is an arch bridge for traffic linking Southwark and the City across the River Thames, in London, England. It was designed by Ernest George and Basil Mott. It was built by Sir William Arrol & Co. and opened in 1921.  The bridge is owned and maintained by Bridge House Estates, a charitable trust overseen by the City of London Corporation.

A previous bridge on the site, designed by John Rennie, opened in 1819, and was originally known as Queen Street Bridge, as shown on the 1818 John Snow Map of London. The bridge consisted of three large cast-iron spans supported by granite piers. It was known as the "Iron Bridge“ in comparison to London Bridge, the "Stone Bridge". The bridge was notable for having the longest cast iron span, 240 feet (73 m), ever made.

Halfway along the bridge on the Western side is a plaque which is inscribed:

Re-built by the Bridge House Estates Committee
of the Corporation of London 1913-1921
Opened for traffic by their Majesties King George V and Queen Mary 6th June 1921
Sir Ernest Lamb CMG, JP Chairman
Basil Mott, CB Engineer
Sir Ernest George RA Architect

The bridge provides access to Upper Thames Street on the north bank and, due to the ring of steel, there is no further road access to the City and the north. This has led to a reputation of it being the least used bridge in central London and it is sometimes known as the "car park bridge" as coach drivers use it to park their vehicles.

The current bridge was given Grade II listed structure status in 1995.