In this chapter, we examine the historical growth of pro bono legal services in Canada and contemporary patterns of pro bono engagement within the bar. We employ mixed methods, incorporating in-depth interviews with lawyers, legal educators, and leaders in the Canadian bar and a large-scale social survey of attorneys. We begin by tracing the historical development of government-funded legal aid in Canada – through the roles of local bar associations and government-led legislation – and the rise of pro bono service in response to declining resources for legal aid. Next, we outline structural factors connected to the diffusion of pro bono service, especially the spread of nongovernmental organizations (NGOs) in Canada, and we identify several distinguishing characteristics associated with pro bono culture in the country. Our discussion leads us to consider professional-based interests associated with the expansion of pro bono and residual areas of contestation between legal aid and private pro bono legal service providers in the quest to improve access to justice.