Local squares function as open spaces where people can conduct many activities and where many social events take place. While squares in Iran have had a historical role in urban life, in recent years they have lost their place as social nodes of neighborhoods. They are losing their sustainability due to diminishing social roles in residential neighborhoods. The primary aim of this research was to investigate social sustainability dimensions in the squares of Narmak neighborhood located in the east of the metropolitan city of Tehran. The research method was descriptive, and 140 questions in seven dimensions were asked from 378 respondents aged 12+, who were selected randomly in 2018. The results showed that social sustainability variables differ in all five types of squares, particularly in terms of sense of place. However, equality was ranked on average as low in all types of squares. This study concluded that social sustainability in residential squares is very sensitive to a rapid urbanization process that has imposed mass apartment blocks, traffic flow, and lack of place identity. As a result, the process has led to social unsafety, low urban security, and weak maintenance of squares, particularly larger squares, as well as the transformation of their role as residential squares to mostly traffic squares and parking spaces. Additionally, this study concluded that small squares are socially more sustainable than larger ones because respondents felt that small squares were safer, more secure, and full of a sense of place. Urban policy-makers can use the results of the present study to evaluate the effects of their executive strategies on urban livability, social sustainability, and the satisfaction of residents.