This chapter explores the nature of online participation as it pertains to political communication. The discussion uses the notion of the public sphere to help understand more about how this concept has changed and needs recalibration to account for a digital public sphere. Audiences are no longer simply passive recipients of information about politics; instead, they can simply and quickly become active participants. In explaining how this can occur, the chapter looks at three examples from recent research that highlights the power of participatory culture in the online space. The first area relates to Internet memes, which are multimodal artifacts capable of simply and economically communicating political expression and engagement. Research has shown that the simplicity of their creation and spread facilitates an avenue to political engagement that would have been absent in the past. The second area focuses on online activism and how online platforms help it proliferate. A final instance of political communication and participatory culture discussed emerged from Twitter/X as a form of “issue public,” where an online discourse community arose out of a satirical response to some particular political commentary. Taken together, these areas highlight the crucial role of social media in contemporary political communication.