This report highlights the breadth and depth of community and citizen science (CCS) contributions to California’s Marine Protected Area (MPA) program priorities and goals as well as participant contributions and outcomes. We examined the CCS efforts of 10 MPA monitoring projects that received baseline and/or long-term funding from the State. They involved 84,000 participants, 476,000 volunteer hours, 528 monitoring sites, and 100 partner organizations, agencies, institutions, and groups. Beyond the 10 baseline and long-term monitoring projects, there are more than 60 additional CCS projects conducting research and monitoring along the California coast. Though demographic data have not been formally collected or reported from these programs, several programs (including two Tribally-led programs) make explicit efforts to engage underrepresented and underserved communities. Though there were more participants in the north and central California coast, the south coast hosted a higher number of monitoring sites within MPAs than the other two bioregions. Some programs overlap within specific MPAs, and participant roles in these programs cover a wide range of different scientific activities throughout the research process. All four pillars of MPA management had some link to the 10 state-funded projects: research and monitoring; education and outreach; enforcement and compliance; and policy and permitting. Our analysis hints at the scale of the public’s desire to participate in science on the California Coast, but also raises the question of what untapped interest and capacity remain, particularly in underrepresented communities. Future work could investigate participant demographics, learning outcomes and other participant benefits, and participant motivations and engagement patterns. There is also potential for greater coordination between project leaders of coastal CCS programs, and desire from participants to see how CCS data are used by managers and policy makers.