This thesis is comprised of three studies examining the effects of pet ownership on street-involved youth in Ontario. As a relatively new area of study, issues surrounding pet ownership among homeless youth were first explored qualitatively. The first two studies utilized a series of one-on-one interviews with both pet-owning youth and youth service professionals to determine the major roles, relationships, challenges and effects that pets have in the lives of street-involved youth. The four themes that emerged from both of these interview groups included “pet before self” where youth placed the needs of their pet ahead of their own, physical effects of pet ownership, emotional effects of pet ownership, and the benefits and liabilities of pet ownership. Findings related to these themes, such as the strength of the human-animal bond and pets as drivers of change are discussed. Information derived from the qualitative interviews with pet-owning youth and youth workers contributed to the development of a questionnaire administered to a convenience sample of 89 pet-owning street-involved youth and 100 street-involved youth who were not pet owners in four urban centres in Ontario. This study sought to validate findings from previous qualitative research, provide descriptive information on the pet-owning youth population, their pets, and their human-animal relationship, as well as assess pet attachment based on the Lexington Attachment to Pets Scale. Additionally, pet owners and non-pet owners were compared in terms of depression based on the Center for Epidemiologic Studies Depression Scale, shelter use and drug use. The findings include a universally high level of pet attachment among this unique pet owning population, providing opportunity for youth to experience not only beneficial emotional and social support, but also the negative emotional consequences of pet loss. Pet ownership was also demonstrated to be significantly and negatively correlated with regular shelter use. Through logistic modelling and controlling for participant gender and regular drug use (of drugs other than cigarettes, alcohol, and marijuana), pet ownership was found to be negatively associated with depression. Using both qualitative and quantitative methodologies, this thesis provides evidence of the beneficial as well as the potential negative impacts of pet ownership for street-involved youth. It also provides the first quantitative description of this population and their human-animal relationship, while demonstrating support for further research into the effects of pet ownership on street-involved youth, and consideration for expanded education and service provision to support youth and their pets among youth services.