Mass media refer to means of communication that reach a relatively large number of people. Mass media include eight mediums: radio, television, newspapers, magazines, books, recordings, movies, and digital media such as social media, gaming, and blogging. Mass media are relevant to the study of social movements because they carry movement ideas to a broader audience and give activists leverage in institutional and political processes. More specifically, mass media are important to movements because they provide social movements an opportunity to shape public understandings of social and political problems, as well as a chance to mobilize a broader public to action. This entry briefly reviews the venues available to differentially resourced movement groups, outlines how sociologists study the movement–media relationship, and highlights unresolved issues with which sociologists must contend.