The decision was announced at a meeting in Bonn, Germany after the UN’s cultural committee spent more than a year considering its nomination.
World heritage status is given to sites of “outstanding universal value” with the aim of protecting them for future generations.
In terms of cultural significance, the accolade puts the Forth Bridge alongside the Pyramids of Egypt, the great Wall of China and the Sydney Opera House in terms of cultural significance.
The distinctive red landmark has carried trains over the Forth since 1890. The bridge, which spans the Firth of Forth between South Queensferry on the outskirts of Edinburgh and North Queensferry in Fife, was opened in 1890 after eight years of construction.
Designed by Sir John Fowler and Benjamin Baker, it measures 2529m (1.5 miles), weighs 53,000 tonnes and was at the time the world’s longest multi-span cantilever bridge.
Over 100 years on, the bridge remains an important part of Britain’s rail infrastructure carrying thousands of passengers each day.
The Unesco inspection report stated: “This enormous structure, with its distinctive industrial aesthetic and striking red colour, was built using advanced civil engineering design principles and construction methods. “Innovative in design, materials and scale, the Forth Bridge is an extraordinary and impressive milestone in the evolution of bridge design and construction during the period when railways came to dominate long-distance land travel.”
Tracey Crouch, heritage minister, said: “It’s fantastic news that the UK’s nomination has led to the inscription of the Forth Bridge. Recognition as a World Heritage Site will draw more tourists to the area as well as making sure one of the UK’s great engineering feats stands for future generations.
“The Forth Bridge is an important part of Britain’s shared national heritage, which is why the UK government put it forward as our nomination for World Heritage Site status last year.”
David Mundell, Secretary of State for Scotland, added: “The Forth Bridge is an iconic piece of Victorian industrial engineering which has a proud place in the UK’s rich culture and heritage.
“Being recognised as a World Heritage site is a fitting accolade for this bridge which has played such an important part in the lives of Scots for 125 years.
“The Forth Bridge joins an impressive list – including the Grand Canyon and the Great Wall of China plus, closer to home, New Lanark and St Kilda – which have secured the prestigious World Heritage status. I’m pleased that the UK delegation has been able to secure this status for the Forth Bridge.”