Rockfleet Castle, Tower house in County Mayo, Ireland

Rockfleet Castle is a tower house standing on the shore of Clew Bay in County Mayo. The structure rises several stories with defensive corner turrets designed to watch over the bay and surrounding lands.

Rockfleet Castle was built in the mid-16th century and belonged to Sir Richard Burke, nicknamed Risdeárd an Iarainn (Iron Dick), who held lands around Burrishoole. He married Gráinne Ní Mháille in 1566; she lived in the tower and used it as a base for a fleet of twenty ships. After his death in 1583 she stayed on, and the castle lost its strategic role when she ended her resistance. In the 18th century it passed to the Arbuthnot family, and Owen O'Malley, a direct descendant of Gráinne, repaired it after the Irish Civil War.

The Irish name Carraig an Chabhlaigh means "rock of the fleet", and the English Rockfleet is a loose translation of it; the alternative Carraigahowley spells the Irish name in English orthography. The name is linked to the fleet of twenty pirate ships that Grace O'Malley, Grainne Ni Mhaillle, kept at the tower while she lived there with her husband Richard Burke.

Entry to the tower is strictly prohibited for safety reasons, so the castle can only be viewed from outside. A metal walkway installed in 2015 links the surrounding grassland to the door, keeping the approach usable at high tide. The N59 runs north of the site near Ardagh, roughly seven to eight kilometres west of Newport.

Rockfleet's Irish name, Carraig an Chabhlaigh, means "rock of the fleet", and the English name is a loose translation of it. The name is linked to the twenty pirate ships of Gráinne Ní Mháille's fleet that were stationed there. The tower's top floor holds a fireplace, suggesting it was the main living quarters.