The rapid evolution of digital technologies is transforming the transportation sector in Ireland, with Mobility-as-a-Service (MaaS) emerging as a promising solution to enhance mobility efficiency and sustainability. However, the successful implementation of MaaS in Ireland faces significant barriers, primarily due to the lack of standardized, interoperable, and secure data-sharing frameworks. The mobility data spaces (MDSs) are potential solutions that provide a trusted and secure data sharing among stakeholders, an essential foundation for integrated mobility services. Yet the development of such data spaces in the Irish context is constrained by fragmented data ecosystems, a lack of coherent governance and technical infrastructure, and limited trust among stakeholders, particularly regarding data control and usage. This chapter presents and discusses the findings from a study conducted within the MaaS4IRL (A Trusted and Interoperable Mobility-as-a-Service Ecosystem for Ireland) project ( https://universityofgalway.ie/dsi/maas4irl/ ), funded by the Sustainable Energy Authority of Ireland ( https://www.seai.ie/ ). The study explores the challenges, opportunities, and requirements associated with mobility data sharing in the Irish context. Drawing on the structured workshops with key public and private stakeholders, it identifies critical technical, legal, organizational, and trust-related barriers to effective mobility data exchange. Based on these findings, the study proposes the establishment of the Irish Mobility Data Space (IMDS) as a framework to facilitate secure, standardized, and trustworthy data exchange among public and private mobility stakeholders. The proposed IMDS is intended to support critical areas such as MaaS, EV charging, and infrastructure planning, contributing to a more integrated and resilient mobility ecosystem in Ireland.