Simple Summary Each year, many people around the world get a pet dog. With so many different types and breeds of dogs available, and a variety of sources from which to obtain a dog, the process of getting a dog can be complex. The decisions involved in this process are likely influenced by a variety of human- and dog-related factors and this review explores the factors that appear to be the most important. Abstract Given the prevalence of pet dogs in households throughout the world, decisions regarding dog acquisition affect many people each year. Across the stages of dog acquisition there is potential for practices that may promote or compromise canine welfare. For instance, prospective owners may not fully understand the time, energy and financial commitment entailed in their decision to acquire a dog. Thus, it is pressing that stakeholders, including those working in the canine welfare sector, refine their ability to identify and respond to trends in the behavior of potential dog owners. The motivations, attitudes and behaviors of current and prospective dog owners is a small but growing area of interdisciplinary study. Yet, no synthesis of the evidence exists. To address this gap, this critical review collates data and insights from studies published by academic researchers and animal welfare charities. The most widely reported factors associated with acquisition behavior include: the dog’s physical appearance, behavior and health; social influences, such as trends in the popularity of certain breeds; demographic and socioeconomic factors; and the owner’s previous ownership experience. Overall, the research discussed in this paper highlights that complex interactions likely underpin the various factors that might influence prospective owners’ motivators and behaviors.