The LÉ Samuel Beckett rescued 508 migrants during search and rescue operations off the coast of Libya on Monday.
The Irish Naval Service vessel rescued the migrants after responding to a request for help from the Italian Maritime Rescue Co-Ordination Centre in relation to four separate rubber vessels containing migrants northwest of Tripoli.
The first rescue operation began at 2.20am and the last operation was completed by 12.20pm.
Those rescued are now receiving food, water and medical treament on board the ship.
The vessel will then take them to a designated port of safety.
The LÉ Samuel Beckett has now rescued a total of 2,818 migrants since it was deployed on September 23rd to the Mediterranean Sea to assist with humanitarian operations in the region.
More than 3,740 migrants have drowned on their way to Europe so far this year, nearly matching the figure recorded for all of 2015, according to the UN refugee agency.