Earl of Orrery is a title in the Peerage of Ireland that has been united with the earldom of Cork since 1753. It was created in 1660 for the soldier, statesman and dramatist Roger Boyle, 1st Baron Boyle, third but eldest surviving son of Richard Boyle, 1st Earl of Cork. He had already been created Lord Boyle, Baron of Broghill, in the Peerage of Ireland in 1628 (at the age of only six). He was succeeded by his son, the second Earl. He represented County Cork in the Irish House of Commons and served as Vice-President of Munster. On his death, the titles passed to his eldest son, the third Earl. He represented East Grinstead in the English House of Commons. He was succeeded by his younger brother, the fourth Earl. He was a Lieutenant-General in the Army and a prominent diplomat. In 1711 he was created Baron Boyle of Marston, in the County of Somerset, in the Peerage of Great Britain. His son, the fifth Earl, succeeded his third cousin as fifth Earl of Cork in 1753. See the latter title for further history of the peerages.

Henry Boyle, son and namesake of the Hon. Henry Boyle, the younger son of the first Earl of Orrery, was created Earl of Shannon in 1756.

The Irish placename Orrery came from Gaelic Orbhraighe, which was at first the name of a tribe (Orbh-raighe = "Orb's people"), and then of a territory and a barony.