Analyzing data from a survey of U.S. adults (N = 509), our study examines the role of partisan media in (a) shaping people’s perceptions of the Black Lives Matter (BLM) movement, (b) producing an echo-chamber effect, influencing users to believe that other people have an opinion similar to their own, and (c) creating a polarized public opinion environment, where people hold more extreme perspectives on BLM. Left-wing media consumption was positively correlated with favorable perceptions of BLM, while right-wing media consumption had a negative correlation, suggesting that partisan media could influence users’ own perceptions of BLM. Also, left-wing media consumption was positively correlated with the belief that others held favorable views of BLM, while right-wing media consumption was negatively correlated with such a belief, suggesting that partisan media could affect one’s beliefs about others’ perceptions. Supporting its role in producing an echo-chamber effect, frequent right-wing media usage was associated with a smaller difference between one’s own views and their assessment of others’ views regarding BLM. Finally, there was a positive correlation between left-wing media consumption and having extreme perceptions of BLM, suggesting that the use of left-wing media could play a role in creating a polarized public opinion climate.