This chapter aims to review historical and current theoretical insights into online retailing and relationship marketing. More than 150 empirical and theoretical online retailing and relationship marketing studies drawn from top marketing and management journals have been systematically reviewed. The chapter examines two key areas in online retailing and relationship marketing. First, the evolution of online retailing and relationship marketing from pre-1990s to the present provides a temporal snapshot of changes within fundamental structural components of online retailing and relationship marketing. The key stages of the online retailing market are depicted within the online retail growth model (OLRG model) adapted from Grainer's growth model on organisational development (Grainer, 1972), accommodating environmental dynamics in retailing. Second, this chapter identifies key theoretical perspectives underlying the development of online retailing and relationship marketing practices: They are utility maximisation, resource-based theories, commitment, trust and social network theories, social exchange, social contract theory, value co-creation and privacy calculus. Summary tables for each area highlight key findings, which in turn suggest a series of managerial recommendations for facilitating efficient, effective buyer–seller interactions and maximising sales performance.