The repertoire of socio-sexual and sexual behaviors of cetaceans is relatively unknown. The purpose of the current study was to advance the existing knowledge of socio-sexual behavior of beluga whales through the development of a behavioral catalog that lists the full repertoire of sexual and socio-sexual behaviors. A behavioral catalog was developed initially from 800 hours of observations, collected across a 7-year period from 11 belugas ranging in age (birth to 30+ years), sex, and social groupings. Using this behavioral catalog, observations of eight additional belugas housed between two other facilities were coded for socio-sexual and sexual behaviors. Socio-sexual and sexual behaviors of belugas were similar across all three facilities. Socio-sexual and sexual behaviors involved sequenced behaviors, had lateralized components, and were often subtle in nature. Some of these behaviors overlapped with potentially aggressive actions but showed distinct differences in their form, or topography. Complexity and duration of socio-sexual interactions varied depending on the age and sex of the participating belugas. The development of a complete behavioral catalog, or ethogram, of the socio-sexual and sexual behaviors has profound influences on understanding the mechanisms involved for successful reproduction, a problem that several groups of belugas in their natural habitat are currently facing.