As human use of the oceans increases, marine spatial planning (MSP) is being more widely adopted to achieve improved environmental, economic, and social outcomes. However, there is a lack of practical guidance for stakeholder driven, scientifically informed MSP processes in small island and data‐limited contexts. Here, we present an overview of MSP on the Caribbean island of Montserrat, with a focus on the scientific and technical input that helped inform the process. Montserrat presents an interesting case study of MSP in the small island context as it has ocean uses that are common to many islands, namely small‐scale fisheries and tourism, but the marine environment has been heavily impacted due to volcanic activity. We detail the methods for data collection and analysis and the decision‐making process that contributed to a marine spatial plan. We highlight aspects of the process that may be useful for other small islands embarking on MSP, and lessons learned regarding scientific support, including the need for on‐site scientific support and guidance throughout MSP, the importance of setting clear objectives, working within data limitations and making data accessible, and choosing and using appropriate decision support tools.