Seagrass ecosystems provide many vital services that underpin coastal tourism industries, yet their condition and spatial extent are declining globally due to human-induced pressures. Despite the economic principle that those who benefit from seagrass ecosystem services should contribute to their conservation, sustainable funding mechanisms for seagrass conservation remain underdeveloped. Tourism offers potential to provide this funding through visitor fees, but a critical knowledge gap exists regarding tourists’ awareness of seagrass ecosystems and their willingness to pay for conservation fees. This research addresses this gap on Bintan Island, Indonesia–chosen for its high tourism levels, extensive seagrass ecosystems, and local communities economically vulnerable to further seagrass decline. The study investigated: 1) tourists’ awareness of seagrasses, 2) willingness to pay seagrass conservation fees, and 3) willingness to participate in citizen science activities that contribute to seagrass management. Structured questionnaire surveys were conducted over three months (May to July 2025) resulting in responses from 400 local and 95 international tourists. Findings showed that despite low seagrass awareness, tourists’ willingness to pay (WTP) for seagrass conservation was high where 96% of international and 76% of local tourists showed WTP. Most respondents (79% of international and 74% of local tourists) showed high willingness to participate in voluntary seagrass monitoring and planting activities. The findings suggest the feasibility of implementing tourism-based seagrass conservation model in coastal tourism areas with seagrass ecosystems.