For robots to coexist with us in harmony and be our companion, they should be able to explicitly reason about humans, their presence, the social and human-centered environment, and the social-cultural norms, to behave in socially expected and accepted manner. To develop such capabilities, from psychology, child developmental and human behavioral research, we can identify some of the key ingredients, such as the abilities to distinguish between self and others, and to reason about affordance, perspective taking, shared spaces, social signals, emotions, theory of mind, social situation, etc., and the capability to develop social intelligence through the process of social learning.Researchers across the world are working to equip robots with some of these aspects from diverse perspectives and developing various interesting and innovative applications.This special issue is intended to reflect some of those high-quality research works, results and potential applications.