The importance of inclusive public open spaces in society is crucial for enhancing social equity and community well-being. Applying the universal design approach to public parks will ensure accessibility and a sense of inclusiveness for diverse populations, including individuals with disabilities, the elderly, and marginalized groups. Establishing this context would promote sustainable urban environments by reducing inequalities and advocating for equitable access to public spaces. This study investigates how the application of universal design principles can be integrated into public parks to enhance accessibility, inclusiveness, and environmental sustainability. It achieves this by using a descriptive-analytical approach and recording the researcher’s observations on a study checklist that follows UD guidelines. This research makes a comparative analysis of three parks, Rinku Park in Japan, Tongva Park in California, and Al Azhar Park in Cairo, using criteria consisting of main points: walkways and pavements, ramps, stairs, parking lots, open and green areas, urban furniture, wayfinding, orientation and signage, and restrooms. The objective of this research is to emphasize the significance of universal design in promoting inclusiveness and sustainability in parks. Furthermore, its objective is to identify the physical barriers that restrict individuals from easily accessing and utilizing these parks. The study has implemented the importance of universal design as an efficient tool for achieving inclusiveness and social sustainability in urban public open spaces.