The event, entitled The Last Dance, will take place in front of around 25,000 fans in Stirling’s City Park next August before the band part ways for good.
Runrig were founded in 1973 on the Isle of Skye, starting out by playing wedding receptions before finding fame and taking their brand of Scottish rock all over the world.
They have since recorded 14 studio albums, releasing their final LPThe Story last year, and have been credited with introducing Scottish Gaelic to a wider audience.
Their Play Gaelic record, released in 1978, was the first ever Gaelic pop album comprised entirely of original material. Seventeen years later their song “An Ubhal As Airde” (The Highest Apple) became the first Scots Gaelic language song to enter the UK top 20.
The band’s popularity peaked in the 1990s, when they played in front of 50,000 people on the shores of Loch Lomond in Balloch Country Park.
During that decade they also supported The Rolling Stones, U2, Rod Stewart and Genesis, as well as twice selling out London’s Royal Albert Hall.
“This has been an enormous and difficult decision for us, but through the machinations of longevity and circumstance, we feel that the timing is now right, for a positive and celebratory conclusion,” said Runrig stalwart Calum Macdonald.
Drummer Iain Bayne said the band wanted the concert to be a “celebration” for their fans, but added they would strike the last note of the night with “heavy hearts”.
A number of Runrig’s previous members have been involved with politics. Singer Donnie Munro left the band in 1997 to try to become an MP, losing out to the late Charles Kennedy.
Former keyboardist Pete Wishart is now the SNP’s longest serving MP, retaining his seat of Perth and North Perthshire at last year’s general election by just 21 votes.
Guitarist Malcolm Jones said: “Although the band as we know it will end, its iconic music will live on, as will the Runrig brand.
“Individual members will continue to write songs, record and engage in live performances, whilst there are various exciting Runrig legacy projects in development.”
The final show in Stirling will be preceded by a farewell tour of venues in Germany, Denmark and England, with the stage set for the band to bow out on Saturday 18 August 2018.
Concert promoter Les Kidger said the “momentous occasion” would have a long set list, with the band performing songs from the past four decades. Tickets go on sale on Friday.