While some might think that the study of pets and domesticated animals in the Atlantic world is a relatively recent phenomenon, there were a few pioneering efforts prior to the discipline-defining work of Alfred W. Crosby Jr., William Cronon, Harriet Ritvo, and Keith Thomas. Today, under the influence of individuals like Virginia deJohn Anderson and Erica Fudge, the field is expanding through a willingness to study the agency of nonhuman animals and the relationships that were formed between them and humans of different ethnicities and estates. In the spirit of James Serpell’s call to seek out instances of pet-keeping beyond the 19th-century European bourgeoisie, there is also a focus on the roles and attitudes of Africans and Amerindians in the development of an Atlantic matrix of traditions regarding pet-keeping and domestication. Evidence is mounting that behaviors we associate with pet-keeping today were present from 1492 on, and were not only displayed in the homes of members of the elite. While the comfort and longevity of companion animals might very well have been determined by the status of their humans, the concern demonstrated by humans of lower economic and social standing for companion animals has been found in the archives and early printed works by scholars like Sonya Lipsett-Rivera and Marcy Norton. As with other aspects of this growing line of research, more remains to be done. In any new field or subdiscipline, terminology and periodization remain in flux. However, regular interactions in an Atlantic world certainly only began with Columbus’s first voyage in 1492, while the publication of Charles Darwin’s The Expression of the Emotions in Man and Animals and Anna Sewell’s Black Beauty, both in the 1870s, marked a victory for what had been two human perceptions of other animals that may have always been there, but that were frequently muted: that humans and other animals share the same feelings and similar methods of communication in their common sentience, and that the cruel use of, at the very least, domesticated animals is morally reprehensible and wrong. As much as our interactions with our pets and domesticated animals have shaped them, they have also shaped us in the Atlantic world and, indeed, globally.