Since 2009, Open Access (OA) Week has been celebrated worldwide in October each year. It is an opportunity for librarians to engage with the research community and demonstrate the value that they bring to their organisations in the area of disseminating scholarly output. Although thousands of events have been held since the inception of OA Week, a minimal amount of research has been carried out regarding the impact of these events. This article presents a review of the literature on OA Week and evaluates the effectiveness of three events held during OA Week 2015 in Ireland through the use of statistics and a survey. The three events held during OA Week 2015 in Ireland that were evaluated include: a seminar run by Repository Network Ireland (RNI), a D.E.A.R. (Drop Everything And Read) campaign using OA materials organized by Dr. Steevens' Library, and a collaborative OA seminar between Dr. Steevens' Library and Dublin Institute of Technology (DIT) libraries. The author concludes that a collaborative approach to planning and managing OA week between librarians from academic and other sectors can have tangible benefits both in terms of promoting OA and also promoting the role of the Librarian in the OA movement.