A Scottish engineer, who built many of the canal, roads, and bridges of the Industrial Revolution. His principal works include the Caledonian Canal linking the east and west coasts of Scotland, and the Menai Bridge spanning the strait between mainland Wales and the isle of Anglesey.

Born in Dumfries in 1757, he was apprenticed to a stonemason in Edinburgh in 1780, but was self-taught in his own chosen métier.

He moved to London in 1782, in 1793 was being appointed surveyor of public works in the county of Shropshire, near the Welsh border. His first major engineering work was the nearby Ellesmere Canal, from the River Dee at Llangollen until it joined the Mersey-Trent Canal at Middlewich. This project lasted from 1793 to 1805.

The Caledonian Canal was built between 1803 and 1823, going from Inverness to Fort William, joining together the lochs that form about half its length. He also built the Göta Canal in Sweden.

It is estimated that Telford built about 1000 miles of road and 1200 bridges. He did not contribute to the development of railways, which he did not approve of, though in after years a railway was added to his greatest bridge, the stone suspension bridge covering the 24 km of the Menai Strait to Anglesey. He was famous for working in iron: great iron works include the 45 m span of the Bonar Bridge (1811-1812) and the aqueduct at Congdon on Tern (1793-1794). The Menai Bridge was the final stage in his road from Shrewbury to Holyhead, which completed the road from London and made access to Ireland easier: this project lasted from 1814 to 1825.

Telford also built St Katherine's Docks in London (1826-1828). As an architect he favoured Classicism: one notable example is the church of St Mary Magdalene at Bridgenorth (1792-1793).

First president of the Institute of Civil Engineers on its foundation in 1818, he died in 1834, and his autobiography came out in 1838. He had an interest in literature and was a close friend of the poets Southey and Campbell. The New Town of Telford in Shropshire is named after him.