Go, the low fares airline formerly owned by British Airways, will begin services from Dublin to Edinburgh and Glasgow on September 19.
Go's fares to both Edinburgh and Glasgow, including taxes, start from £45 return and will be no dearer than £140 to Glasgow and £160 to Edinburgh.
Go will fly four times each weekday to Edinburgh, with three flights a day to Glasgow International. The only other low cost services to Scotland are Ryanair's flights to Prestwick.
Go chief executive Barbara Cassani said she was not afraid of taking on the might of Ryanair on their routes.
'I take my hat off to Ryanair's success story, but they should watch out, we're here, we're in number three position, and we are trying harder,' she said.
She said Go planned to offer other British destinations from Dublin including the busy London-Dublin route, however she said there was no precise timing for these developments. She also said Go was considering destinations on the continent, including Malaga, Alicante, Rome and Venice, which the company already flies to from England.
Ryanair's Michael O'Leary welcomed Go's arrival in Dublin, saying he hoped that Go and Aer Lingus would enjoy squabbling with each other for the business of passengers who did not mind high air fares.
'It is dispointing, however, that Go didn't have the courage to challenge Ryanair on the Dublin-London route,' O'Leary said.
Like Ryanair, Go is ticketless, has only one class on board and does not provide free meals in flight. However it does allocate seats at check in, rather than 'forcing passengers to scramble for their seats on boarding,' the airline said.
Go's fares are available at www.go-fly.com or by telephone at 1890 923 922.
Go was founded in 1997 as an independent subsidiary of BA. A management buyout, backed by venture capitalist 3i, was completed a fortnight ago. 22.5% of the company is owned by employees.
Cassani said the company intended a public flotation in the next two to three years. Go operates on 33 routes between 27 European cities.
