The Perth-based group has unveiled orders for 568 vehicles in 2014/15.
The firm, which describes itself as Britain's biggest bus and coach operator, said the set of orders is its largest ever and one which will support hundreds of British jobs.
The move takes Stagecoach Group's total orders of new buses and coaches for its regional UK operations to around £545 million in the last seven years, bosses said. The group has also ordered more than £100 million of new vehicles for its London bus operations since buying the business in 2010.
Of the overall investment in the next financial year, £81 million is being spent on 495 new vehicles to go into service across Scotland, England and Wales.
In addition, a £21 million fleet of more than 70 greener hybrid buses will be introduced to the London operation.
All of the new vehicles will be fitted with CCTV while more than 350 will have wi-fi installed for free internet access.