Tickets will be reduced by 50 per cent on all off-peak weekday services between 9 and 31 May to encourage more people to travel by rail.
ScotRail said it had planned to launch the “Yours to Use” initiative in January – when its fares increased two months ahead of the rest of Britain – but it was postponed by an increase in Omicron cases.
Tickets peakwill have to be booked online through a specific link.
They will be available to order from 9 to 15 May, and return travel must be completed by 30 June.
Savings include off-peak returns between Edinburgh and Glasgow for £9.55 compared to £19.10 normally
Dundee-Edinburgh off-peak returns will be cut from £30.70 to £15.35.
The promotion comes as ScotRail is lagging behind some operators such as LNER in rebuilding passenger numbers after Covid travel restrictions were eased.
It has only returned to about 60 per cent of pre-pandemic levels, with Saturdays now its busiest day.
Scotland also only removed the requirement to wear face coverings on trains and other public transport on Monday.
ScotRail’s fare increase was 3.8 per cent, the highest for nearly a decade, which was based on an established formula linked to the inflation rate.
Other operators increased their ticket prices by the same amount in March, although the Scottish Government said ScotRail’s off-peak fares remain about 20 per cent cheaper than south of the Border.
The UK Department for Transport fares offer, which includes cross-Border operators like LNER and Avanti West Coast, runs from 25 April to 27 May.
ScotRail commercial director Lesley Kane said: “The pandemic has fundamentally changed the way people travel, and it is an absolutely priority for ScotRail to do everything we can to attract customers to Scotland’s Railway.
“We are launching this fantastic offer because Scotland’s Railway is ‘Yours to Use’.
Chris Gibb, chief executive officer of Scottish Rail Holdings, which oversees ScotRail on behalf of the Scottish Government’s Transport Scotland agency, said: “Passengers up and down the country have been impacted by the pandemic, not least in the cost of living crisis we are currently facing.
"We want people to come back to rail but know that we need to make it affordable to be a truly attractive alternative to using the car.
“This fares offer, backed by the Scottish Government, is one of several initiatives ScotRail have been working on for delivery in the coming months to encourage people back on to our trains.
“The Scottish Government appreciates this is a short term offer – that’s one of the reasons why it has committed to a fair fares review, which will consider public transport across differing modes and which will also look at affordability."
The move was welcomed by Scottish Greens transport spokesperson Mark Ruskell, who said: “With Greens in government, we’ve already delivered free bus travel for young people and I’m pleased that there’s now a focus on making rail travel more affordable.
“It’s vital that we explore every avenue to support people as the Tory cost of living crisis bites and I’m sure this rail fare reduction will be positively received by the public.”