Based on the persuasive press inference, this study examined the role of partisan sources and audiences’ involvement in their perceptions of public opinion. An online experiment (N = 221) was conducted in South Korea. This study found that partisan sources indirectly affected audiences’ perceptions of public opinion by influencing their perceived news slant. Audiences’ value-relevant involvement, rather than outcome-relevant involvement, significantly moderated the effect of perceived news slant on their perceptions of public opinion. Moreover, the indirect effect of partisan sources on the perceptions of public opinion was stronger for those with higher levels of value-relevant involvement. The implications of these findings were discussed.