Content and Language Integrated Learning (CLIL) is a dual-focused educational approach in which an additional language is used for the learning and teaching of both content and language (Mehisto, Marsh, and Frigols, 2008). While the integration of language and content teaching is well established in Irish language immersion programmes, there is an acknowledged lack of acquaintance with the variety of theoretical approaches that are available to other language teachers, a dearth of Irish language CLIL materials, and a lack of teacher education programmes to prepare language and subject teachers for CLIL (McKendry, 2007). This chapter presents the outcome of collaboration between two communities of practice which traditionally may have been perceived as distant cousins. While both are concerned with the role and place of language/s in the curriculum, neither until recently had exchanged knowledge and experience for the benefit of teachers, student teachers, and, ultimately, learners. Since 2009, the National University of Ireland (NUI) Galway, through An Dioplóma Gairmiúil san Oideachas, the sole initial teacher education course for second-level teachers through the medium of Irish in Ireland, and Waterford Institute of Technology (WIT), through its expertise in Content and Language Integrated Learning, have collaborated in ways that have expanded the perspectives of both communities. This chapter outlines the background, rationale and context for this collaboration, which led to change and innovation in initial teacher education (ITE). Moreover, it points to the benefits that can be gained from interdisciplinary collaboration as a result of common concerns for the future of language education in Ireland, including language issues experienced in English, the dominant language. While these concerns are real, they also present opportunities for change and the development of interdisciplinary mind-sets within teacher education and the teaching world at large. New avenues are opened when the potential of placing language along with content as joint curricular objectives is considered and when the relationship between language and learning is re-asserted. In this respect, Content and Language Integrated Learning has much to contribute.