The seven electric-hybrid double decker vehicles will cover the Kirriemuir, Forfar and Brechin 20 and 21 routes to and from Dundee.
The Scottish government's Scottish Green Bus Fund has contributed £300,000 towards the cost of the vehicles, which include free wi-fi access.
Stagecoach introduced 18 electric hybrid buses in 2015, which run on the 73 route between Dundee and Arbroath.
Jon Oakey, Stagecoach East Scotland acting general manager said: "We're committed to improving public transport in Angus and Dundee so I'm delighted to be introducing our latest investment for the area.
"These new vehicles will complement our existing 18 electric-hybrid buses already in the area, helping reduce our environmental impact and hopefully encourage more customers to opt for our greener, smarter travel."
Stagecoach has launched its new £2.1m fleet of buses in Dundee and Angus.