Socio-cultural dimensions and values in maritime spatial planning (MSP) are gaining momentum worldwide and especially in the European Union (EU), since it is acknowledged that they are the “missing layer” of maritime spatial plans (MSPlans). These values are partly explored through cultural ecosystem services (CES). Coastal and marine CES refer to the benefits that humans derive from the coastal and marine environments in recreational, artistic, spiritual, and educational terms. They reflect the ways in which coastal and marine ecosystems contribute to human well-being, cultural identity, and interactions with nature. The research question is how to map and assess coastal/marine ecosystem services and to integrate them in the MSPlans. Thus, this systematic review sheds light on methodological and technical issues with CES mapping and assessment and provides guidance on how to incorporate CES in MSP for future research. Publications dealing with the spatial aspects of CES were examined with an extra focus on participatory mapping approaches. Initially, 199 articles were identified, and 50 articles were ultimately eligible for the analysis. Papers were concentrated in the European Atlantic, whilst their scope was either local or regional. A large number of articles consider the contribution of CES to efficient marine management rather than to achieving an integrated and coordinated MSP. Social and mixed mapping approaches were met with the most often, especially participatory mapping approaches. Also, non-monetary valuation was prevailing, and a multitude of techniques, tools, and statistical software were used. In most of the cases, the distribution of values in relation to environmental, socio-economic, and demographic factors was examined. This article concludes that an effective integration of CES into MSP is crucial for creating prospects of a more sustainable and inclusive approach to coastal/marine planning and for the well-being of ecosystems and communities both currently and for future generations. This knowledge should become “property” of the maritime spatial planners.