The Cooley Peninsula is a hilly peninsula in County Louth, Ireland, which includes towns such as Omeath, Carlingford and Greenore, and the mountain Slieve Foy. To the north is Carlingford Lough and the border with Northern Ireland; to the south is Dundalk Bay.

In Irish mythology Cooley (Old Irish Cúalnge) was the home of the bull Donn Cúailnge, and the site of the Táin Bó Cúailnge or Cattle Raid of Cooley. Ancient monuments in Cooley include the Proleek Dolmen, whose capstone weighs an estimated 46 tons (46.7 tonnes), and a Bronze Age gallery grave, both near Ballymascanlon.

The Cooley Peninsula is the home of current Irish rugby player, Rob Kearney.