The role of selective exposure in the relationship between online news use and political participation is examined. American adults (N = 205) completed a 2-session online study that measured political interest and online news use, unobtrusively observed selective exposure, and finally measured political participation likelihood. Online news use and selective exposure to attitude-consistent information were modeled as sequential mediators between political interest and participation likelihood. While greater political interest increased both participation likelihood and online news use, online news use ultimately depressed participation likelihood by reducing selective exposure to attitude-consistent news. The findings demonstrate that selective exposure is a fundamental process that must be considered when testing the effect of Internet use on political participation. © 2013 International Communication Association.