The Union Canal is a 31.5 mile (50.7 km) contour canal in Scotland, from Lochrin Basin in Edinburgh to Falkirk, where it meets the Forth and Clyde Canal. It was originally known as the Edinburgh and Glasgow Union Canal, to celebrate the uniting of the two cities by the new canal network, but this name is rarely used today.

The canal was designed by Hugh Baird who oversaw the engineering work while it was being built between 1818 and 1822. Two of its construction workers were the famous murderers Burke and Hare.

The soliton was first demonstrated on the Union Canal in 1834. A modern aqueduct over the Edinburgh City Bypass is named after the discoverer of the soliton, John Scott Russell.

Originally used for transporting coal, competition from the railways caused it to close to commercial use in the 1930s. The locks connecting it to the Forth and Clyde Canal at Falkirk were filled in and built over.

The canal is now used recreationally by canoeists at the Forth Canoe Club and rowers from schools and St Andrew Rowing Club. The Edinburgh, Ratho and Linlithgow Canal Societies promote general use of the canal and hire rowing and narrowboats.

The Millennium Link (a project to restore both the Union and Forth and Clyde Canals) saw the two canals joined once again at the Falkirk end of the Union Canal, in the year 2000, by means of the Falkirk Wheel.

The Union Canal is a contour canal, following a 73 metre (240ft) contour throughout its length. Originally the only locks were those at Falkirk to make the link to the Forth and Clyde canal. Now there is one lock just before the Falkirk Wheel and a double lock just above. There is also a new tunnel where the canal crosses the Antonine Wall.

The canal has many aqueducts, including the Slateford Aqueduct that takes the canal over the Water of Leith in Edinburgh, the Almond Aqueduct near Ratho and the 810ft long Avon Aqueduct near Linlithgow, the second longest in the United Kingdom.

The Edinburgh end of the canal no longer reaches the site of Lochrin Basin, which was filled in after the canal closed. Instead the canal stops a little to the south and west of Lochrin Basin, at the site of another basin at Fountainbridge. This area is currently being redeveloped as Edinburgh Quay for commercial and residential use.

With the canal now largely restored for both boating and for walkers and cyclists on the towpath it is enjoying new life. Holiday barges are common in the spring and summer, while in area nearer the city centre there are even year-round residents living on barges while 'floating restaurant' barges sail most evenings where you can enjoy a meal and a cruise. Local rowing clubs continue to use the canal (notably from the universities in the city) and on June 30th 2007 a raft race was held at the final section near Fountainbridge, behind the now disused Scottish and Newcastle Brewery along to the end of the canal at Tollcross, close to the original home of Sir Sean Connery, all using found 'junk' material.