Millennials are the world's digital natives and its largest generation. A general perception of this generation is that they lack engagement in social-political issues. This study explores how Millennials are engaging in social media activism and whether online activism is driving offline activism behaviors. A quantitative survey of 306 participants was conducted to learn more about the gratifications Millennials obtain through social media and whether associations exist between their online and offline activism behaviors. The results showed that Millennials engage in online activism behaviors to a greater extent than offline activism behaviors. Millennials primarily gratify intrinsic needs for interaction and belonging by engaging in social media activism behaviors. So-called “slacktivism” behaviors were most common among Millennials engaging in online activism. Similarly, online activism behaviors that require greater investment from Millennials were a good predictor of activism behaviors that occur offline. Results also demonstrate that, at an individual identification level, Millennials self-perceptions as activists predicted engagement in both online and offline activism.