The new service will start at the end of April
Brittany Ferries is to launch the first ever direct ferry link between Ireland and Spain.
The new service, which starts at the end of April, will see two direct sailings weekly from Cork to Santander.
Tickets for the new route will go on sale at the end of January.
The announcement comes as Brittany Ferries celebrates its 40th year in Ireland.
The Cork to Roscoff route opened on St Patrick's Day in 1978 and has brought millions of French passengers to Ireland.
A new ship - to be called Connemara - will be chartered to serve the route to Spain, and to deliver an additional weekly return-sailing from Cork to Roscoff.
As well as opening a new route, the ship will also add capacity to the company's existing line to France.
Hugh Bruton is general manager of Brittany Ferries Ireland: "This is a significant move for Brittany Ferries, offering haulage companies a direct route to Spain and passengers a far greater range of holiday options from Cork.
"As a destination so-called green Spain promises visitors a wealth of opportunities.
"It hosts sweeping sandy beaches, snow covered mountains just an hour from the port, fabulous food and offers visitors a welcome as warm as the Spanish will receive when they join us in Ireland."
The ship is currently operating on routes between Italy and Greece and will be chartered from Stena RoRo for an initial period of two years.
It will carry around 500 passengers with space for 195 cars.