In the Irish context, colonialism involves a history of colonisation and a post-colonial period of decolonisation. This paper explores psychological aspects of colonialism in the general framework of a feminist psychological oppression and liberation. An interdisciplinary approach is used which emphasises the interaction of psychological and social processes over generations and which highlights gender effects. The impact of colonialism on Irish society, drawing on Irish writings in history, social sciences, cultural studies, and feminism is considered initially. This involves highlighting the historical legacy of colonisation and considering characteristics of modern Irish society which can be linked to colonisation. The discussion then focuses son psychological patterns associated with colonisation, with the post-colonial situation and with decolonisation. By linking the process of decolonisation with feminist analyses of liberation, it is suggested that modern Ireland offers a unique opportunity for understanding liberation processes generally.