Play and playfulness have been seminal to human culture for millennia. Twentieth-century scientific enquiry was largely concerned with their evolutionary benefits, though humanistic psychology, and later positive psychology came to view them as attached to greater human values and meaning creation. Due to their myriad forms and manifestations, play and playfulness have been difficult to define and measure. This paper will explore the nature of these problematics. It will also highlight the most salient research concerning the benefits of play and playfulness, and the subsequent implications for coaching. Based on the latest literature, a definition of play and playfulness apposite to the coaching framework is offered, along with suggestions for future research directions.