The Government is setting aside €15m to ensure the continued operation of five ferry routes from Dublin and Rosslare for a minimum of three months.
The move follows a request for help from ferry companies who have seen numbers collapsing on their Irish routes since the start of the Covid-19 crisis.
Routes to be protected under "public service obligation" designation are Rosslare-Cherbourg, Rosslare-Bilbao, Rosslare-Pembroke, Rosslare-Fishguard and Dublin-Cherbourg.
The ferry companies involved are Irish Ferries, Stena and Brittany Ferries.
According to Minister Paul Kehoe, the move was "essential" to keep the routes viable.
"This emergency measure is extremely welcome given the huge collapse in tourism that is affecting the entire industry," he said.
"It is also vital to ensure the protection of supply chains," he added.