But Mr O’Leary insisted he remained committed to struggling Prestwick Airport, despite also revealing the number of routes there next summer will be reduced from 24 to 16 in 2015.
Glasgow’s new flights will be to Chania in Crete and Carcassonne in France, from next summer.
They will bring the total to nine, after Ryanair launches its first flights from the airport in October.
Mr O’Leary, who is expected to announce two more routes from Edinburgh later today, said Prestwick would continue to struggle unless air passenger duty was cut, which he said put off many potential passengers.
Ryanair will effectively switch seven routes from Prestwick to Glasgow in October - Carcassonne, Chania, Derry, Dublin, Riga in Latvia, and Warsaw and Wroclaw in Poland - and will no longer fly to Knock in Ireland from the west of Scotland.
Eleven of Prestwick’s remaining routes next summer are to Spain, with the remainder to Italy, Greece, Portugal and Malta
Mr O’Leary said the airline now only covered its costs at Prestwick, after previously making “quite a bit of money” there, and warned that if it started making losses it could pull out.
He said: “We are a break-even operation there. If it starts to lose money, we wouldn’t think twice of leaving.”
He added that Ryanair’s major maintenance base at the Ayrshire airport would remain “whether we fly to Prestwick or not”.
However, Mr O’Leary said the airport provided a competitive edge for Glasgow’: “Prestwick has lower costs and It keeps Glasgow honest”.
Mr O’Leary declined to express a view on Scottish independence but said the scrapping of APD - the SNP has pledged to at least reduce it - was crucial, regardless of the referendum vote.
Passengers pay £13 in APD on flights from UK airports on short-haul routes which Ryanair operate.
He said: “It is a major disincentive to visitors coming to Scotland and one of the reasons we have struggled to grow the business at Prestwick.
“The future for Prestwick remains challenging while you are under the yoke of APD.”
He said Glasgow Airport would “continue to be a focus area for our growth” and it offered the same growth potential as Edinburgh, where Ryanair has 32 summer routes.
He said: “The range of services at Glasgow is pretty narrow. There is not enough spread of flights to other European cities.
“Glasgow Airport has seen how fast we have grown at Edinburgh and want to share in that growth.”
Ryanair increased its routes from two to 23 in 2008.
Mr O’Leary said there would no new routes launched from Edinburgh next summer because of a shortage of new aircraft, but he signalled expansion from winter next year after another batch of new planes arrive from Boeing.
However, there will be more flights on the existing Barcelona, Pisa and Rome routes.
The chief executive said the planned growth would make Ryanair Edinburgh’s biggest airline. It is currently third, behind EasyJet and British Airways, with one in five of the airport’s passengers - 2 million.
He also pledged to peg return fares between the capital and Stansted below £100 after Ryanair starts competing with EasyJet on the route in October, even for those booked the day before travel. He compared that to a £180 EasyJet fare that was available today for a flight tomorrow.
Mr O’Leary said: “We are talking to them [Edinburgh Airport] about new routes in winter 2015 when we will have 35 new aircraft arriving from Boeing.”