The festival is the high point of a year-long celebration marking the founding of the town in 1812. The festival aims to celebrate the town's founding father, John D'Arcy and Clifden's rich culture and heritage.
Activities include walks, drama, a regatta, street theatre and a large street party. It's hoped that the festival will give the local economy a boost and entice more visitors to the town.
RTÉ's Ryan Tubridy started the festivities on Saturday night in the town square.
A calendar of events can be found at www.clifden2012.org