Urban plazas provide opportunities for children to play, learn and explore. In particular, public art in urban plazas can be a medium to absorb more children. This research has developed the Inclusive Urban Plaza Design (IUPD) assessment tool, which complies with the principles and features of urban plaza design based on the children’s preferences, needs, wishes, and perceptions for their healthy growth. The AHP (Analytical Hierarchy Process) decision-making method was applied to measure the weights of the feature. AHP analysis determined that motor skills (W
C1.1 = 0.127) have the highest impact on children’s growth among all sub-criteria, followed by space shape and size (W
C2.1 = 0.100) and cognitive development (W
C1.6 = 0.097). The IUPD toolkit was implemented in Vivacity plaza in Singapore to be validated. The implementation analysis showed that Vivacity plaza was a ‘gold’ grade. It is a well-designed urban plaza that supports children’s growth through interaction with various shapes, colors, textures, and materials (like sand and water) that children love. However, it needs minor improvements in terms of inventiveness and creativity (WSMC1.4 = 0.65), cognitive development (WSMC1.4 = 0.57), and time and program schedule (WSMC2.7 = 0.65). The IUPD toolkit showed to be a universal tool that can evaluate the performance of urban plazas in children’s growth.