The current tower house resembles Leamaneh Castle in that it was constructed over a prolonged period. The oldest part is the tall eastern tower, likely built in the 15th century. In 1564 the O'Connors lost their territory and in 1584/5 the castle was formally ceded to Sir Turlough O'Brien. Following the 1641 rebellion and subsequent Cromwellian reorganization, Turlough's son Daniel petitioned the English Commission in 1654 to save the house from demolition. Either he or his son, Teigue, eventually built the expansion at Ballinalacken. Teigue's son in turn, Donough, styled himself "of Ballyneleackan". The house remained in the possession of the Ennistymon O'Briens until the middle of the 18th century, when it passed to a different branch of the family. The Ballinalacken O'Briens trace their descent from "Turlough Don" who died in 1528, and also from the Ennistymon branch of the O'Briens, which was founded by Sir Donald O'Brien of Dough Castle (Lahinch) who died in 1579. In 1641-2 it was held by Daniel O'Brien of Dough and in 1654 a Cromwellian officer ordered the castles of Dough and Ballinalacken to be preserved from the dismantling of fortifications. In the 1667 Act of Settlement a Captain Hamilton became owner, but the O'Briens regained possession. The O'Briens were one of the most powerful families in Ireland at the time and built several castles - of which Ballinalacken is one. In 1837 its owner was planning to repair it.