This chapter provides an overview of the epidemiology of human papillomavirus (HPV) infection, with a focus on the dynamics of sexual transmission. We explore concepts related to the spread of sexually transmitted infections, including population prevalence, duration of infectivity, patterns of sexual contacts, and transmissibility, including modifiers of susceptibility and infectivity. HPV prevalence and incidence are high in most studies, particularly amongst young women. There is strong evidence that transmission occurs primarily via sexual activity, most commonly vaginal and anal intercourse. Although the duration of infectivity may be short, current evidence suggests that HPV is highly transmissible. The implications of transmission dynamics for the success of future HPV vaccines are discussed.