Veterans and serving soldiers will also be at the service in Dundee to remember the thousands who lost their lives in one of the biggest battles of the First World War.
Around 21,000 British soldiers were killed in the war in 1915 with Dundee particularly hit hard with a large number of the casualties coming from the 4th Black Watch based in the city.
The City Square will today be transformed into what's been described as a "cathedral", with four church leaders from Dundee representing the Scottish Episcopal, Roman Catholic Church of Scotland, Church of Scotland and the Chaplain General to the Armed Forces.
The service will begin with a parade and will see Charles, known as the Duke of Rothesay in Scotland, laying a wreath against a specially-commissioned memorial stone.
Speaking ahead of the event, Ms Sturgeon said: "With around 30,000 Scots serving at Loos, its effect was felt throughout every village and town in Scotland.
"The weekend of national commemorations will be a fitting tribute to those that fought, those that died and those that were left at home."