This chapter explores Theory of Mind (ToM), an important social-cognitive skill emerging between the ages of three and five years. ToM is the understanding that people have unique perspectives that influence behaviour, potentially differing from one’s own. Children denied or blocked neurodevelopmentally from access to linguistic, conversational, or socio-environmental opportunities tend to have lifelong difficulties. Dysfunctional ToM has been identified in over 30 different mental disorders. Deaf and hard of hearing (DHH) children may be at risk for deficits or delays in the development of ToM due to minimal conversational access and an absence of other extralinguistic influences. This chapter will describe the development of a ToM screener, as well as modules for teaching ToM to DHH children showing delays.