Marine renewable energy (MRE), which includes wave, tidal, and offshore wind energy, has the potential to make significant contributions towards a sustainable energy future in a number of countries worldwide. One such country is Spain, where MREs are among the largest renewable resources; yet they are not playing their full part in the national energymix. Among other constraints, the lack of a specific policy framework promoting this emerging sector is often pointed to as the main barrier for MRE grid penetration. This paper assesses the Spanish MRE sector, in terms of resource availability, government plans, policyregulations, and projects undertaken, with a view to establish a comparison with the situation in other European countries. In particular, the United Kingdom is used as a case study to analyze ongoing research activities, pilot projects, and lessons learned. As a result, it is found that public funding needs to be increased; the economic crisis should be seen as an opportunity for job creation and industrial development rather than a barrier; administrative procedures must be simplified and cross-national cooperation should be increased. Policies focused on these aspects may contribute to boost the MRE sector in Spain.