The benefits of nature exposure on human health, mental well-being, and overall quality of life are widely recognized. In urban environments, public green spaces play a crucial role in mitigating climate change, improving air quality, restoring biodiversity, and addressing social challenges such as poverty, inequality, and minority segregation while fostering a reconnection with nature. This study investigates the social and environmental services provided by five distinct public green spaces in Faro, Portugal, varying in typology and vegetation density. To explore these dynamics, we employed two complementary methodologies. First, a survey was conducted among a random sample of 300 Faro residents to assess personal characteristics, health and well-being, perceptions of key green spaces, visitation frequency, and the perceived impact of these visits on individual well-being. Simultaneously, field assessments combined with satellite imagery allowed for a detailed inventory of tree species within the selected green spaces, including measurements of trunk circumference and conservation status. The collected data was analyzed using the My-tree tool to quantify key ecosystem services, such as carbon sequestration, stormwater regulation, and air pollutant removal. Results indicate that green spaces with higher tree density and significant blue infrastructure positively influence residents’ well-being. Among them, Mata do Liceu was identified as the most effective in mitigating climate change. Moreover, findings suggest a negative correlation between self-rated stress levels and the frequency of visits to green spaces, reinforcing the crucial role of urban nature in promoting mental health.