At 10pm, public buildings and offices will turn off all the lights, leaving just a single candle or bulb to illuminate them for an hour as they reflect on the start of the outbreak of war 100 years ago.
The initiative was inspired by then Foreign Secretary Sir Edward Grey's remark at the outbreak of the First World War: "The lamps are going out all over Europe. We shall not see them lit again in our lifetime."
As part of the Lights Out project, artist Nalina Malani will present a large-scale video projection across the western and southern facades of the Scottish National Gallery in Edinburgh.
Glasgow City Chambers is among the buildings taking part. The city council plans to turn off all the lights in its headquarters. From 10pm only a single light overlooking George Square will burn. On the stroke of 11pm it will be switched off to mark the start of the war.
A vigil will start at 10pm in Glasgow Cathedral and will finish at 11pm with a single candle being snuffed out.
Organisers of the UK-wide project hope members of the public across the country will also switch off their lights at 11pm to reflect on the conflict.
Glasgow Lord Provost Sadie Docherty said: "We hope this highly symbolic gesture will allow everyone in our city to remember their fellows citizens who took part in World War 1.
"Some 18,000 Glaswegians never returned from the war and Glasgow, like towns and cities the length and breadth of countries throughout the world, was never the same again."