Marine spatial planning (MSP) offers an operational framework to address sustainable and well-planned use of ocean space. Spatial allocation has traditionally been single-sector, which fails to account for multiple pressures on the marine environment and user conflicts. There is a need for integrated assessments of ocean space to advance quantitative tools and decision-making. Using the example of offshore wind energy, this article offers thoughts about how MSP has evolved in the United States and how the varying scales of MSP achieve different outcomes. Finally, a review of quantitative and qualitative studies that are needed to support MSP are presented.Key Words: MSP, Tradeoffs, Stakeholder Engagement, Offshore Wind EnergyThe oceans and coasts host countless recreational, commercial, scientific, and security-related activities that often occur near the areas determined as and managed for resource protection and conservation goals (The White House Council on Environmental Quality 2010). Today, human activities -fishing, shipping, cable crossings, pipelines, and recreational activities -require a considerable amount of ocean space and place stress on marine ecosystems. Marine spatial planning (MSP) considers the interaction among various uses of the ocean in spatial and temporal scales and represents a powerful method for reconciling diverse and often seemingly overlapping needs of ocean users. As human development has expanded on land, constraints and future developments have long been managed through land use policies that employ zoning and land use restrictions (e.g., Sanchirico et al. 2010), but