The origin of the animal rights movement (ARM) is usually traced to nineteenth-century anti-vivisectionist campaigns in Britain. After a lull, the ARM re-emerged in the twentieth century and is now found across the world. Like other social movements, the ARM uses various methods to influence views and mobilize support. This entry explores the complexities of the ARM as a social movement, including origins, membership, and media responses. It considers the notion of “rights” and examines the differences between “abolition” and “welfare” – issues that are so important to our understanding of the ARM.