Transportation of oil and other harmful substances by sea poses great risks of causing harm to human health or welfare and the marine environment. With a view to protecting the marine environment from pollution and its resources a number of legislative measures have been adopted, and are under way, at the global, regional and national levels. For the purpose of the protection of Irish waters from pollution, a set of legislative measures in accordance with the relevant international conventions have been adopted in Ireland. However, there is difference between global regulations and Irish laws, that is, Ireland’s marine pollution Acts in addition to civil liability impose criminal liability under certain conditions upon the polluter of the marine environment. In this paper we examine the existing Irish laws establishing criminal and civil liability, including insurance and compensation for marine pollution. Beginning with the consideration of the importance of shipping and maritime transport to Ireland, this paper reviews spill experiences in Ireland and then analyses Irish criminal and civil legislative measures, making a distinction between different sources of marine pollution.