Rockfleet Castle (Carraig-an-Cabhlaigh), also known as Carrickahowley Castle is a tower house on the Wild Atlantic Way, near Newport in County Mayo, Ireland. Situated at the mouth of a small inlet on the northern shores of Clew Bay, 5 miles from Newport on the north west coast of Ireland. Built over 4 floors, over 60 feet or eighteen metres in height, the site consists of a tower house with a rectangular corner parapet set in open ground. The top floor is reached by a spiral staircase made of stone and is the only room with a fireplace. The castle was built in a medieval style and is one of five along the shores of Clew Bay.

The castle is renowned for its links with Grace O`Malley (or Granuaile), a pirate sea Queen who inhabited the castle in the latter part of the 16th Century. Home to Grace O'Malley the Pirate Queen and her husband Richard Burke Richard of Iron from 1566. Grace was the leader of the O'Malley clan and controlled much of the west coast in the late 1500's. She had a fleet of 20 ships moored at Rockfleet which she used to raid cargo ships along the channel and was also responsible for capturing some of the dispersed ships from the Spanish Armada. Grace was reputed to have command of three galleys and some 200 fighting men with which she was able to give the merchant ships to and from Galway a hard time. In fact she became so successful in this that, in March of 1574, the English sent an expedition of ships and troops to put an end to her maritime exploits. They laid siege to the castle for many days but Grace turned the tables on them and the hunters became the hunted.

She remained at Rockfleet Castle after the death of her husband in 1583 but it was not long afterwards that the English successfully captured some of the O'Malley fleet along with Grace's brother. Grace appealed directly to Queen Elizabeth for his release and negotiated that she would forfeit her ships in return for her brother. The Queen granted Grace what she had asked for and allowed her to keep her vessels on the condition that she fought with, rather than against the English, which she did until her death in 1603 when she was buried on Clare Island nearby. Following the Civil War Sir Owen O'Malley a diplomat and descendent of Grace restored the castle and lived nearby in a Georgian house. The latest owner is the former American ambassador to Ireland.

Rockfleet Castle is open to the public during the summer; the key is available at the nearby farm. The castle was installed with a metal walkway in 2015, from its adjacent grassland surrounding to its door, due to the sheer inconvenience of accessing its entrance during high tides. It also possible to take a trip into the bay by fishing boat from the nearby pier. From the sea you can see how well the castle was placed to keep watch over the bay.