Although research on fathers tends to focus on mother-derived conceptualizations of caregiving, such as sensitivity, it has been theorized that fathers play a unique role in opening their children to the world by encouraging exploration and risk-taking. However, extant research on these forms of paternal caregiving is scattered across multiple related but distinct domains, namely rough-and-tumble play, challenging parenting behavior, and the activation relationship. Based on the overlap in theory and operationalizations of these domains, the present review aimed to define and operationalize a new caregiving construct: activation parenting (AP). Fathers who exhibit frequent and high-quality AP behaviors encourage children to take risks, challenge children physically and socioemotionally, and set appropriate limits during stimulating interactions to ensure safety and prevent over-arousal. Using Belsky’s (1984) process of parenting model as a foundation, associations between paternal AP and characteristics of the father, his environment, and his child are reviewed, with a focus on early childhood (i.e., ages 0–5 years). The present review found some support for paternal AP occurring more frequently, but not necessarily with higher quality, when fathers had children older than one years old. Unexpectedly, the frequency and quality of paternal AP did not differ much by paternal age or indicators of socioeconomic status, or by child age or gender. In line with underlying theories, higher quality paternal AP in early childhood has been found to be associated with children’s self-regulation skills and lower levels of internalizing and externalizing problems. Limitations of the current paternal AP literature are discussed and future directions for research, policy, and clinical work are proposed.