Misinformation is widespread, but only some people fall for the false information they encounter. This raises two questions: Who falls for misinformation, and why do they fall for misinformation? To address these questions, two studies investigated associations between 15 individual-difference dimensions and judgments of misinformation as true. Using Signal Detection Theory, the studies further investigated whether the obtained associations are driven by individual differences in truth sensitivity, acceptance threshold, or myside bias. For both political misinformation (Study 1) and misinformation about COVID-19 vaccines (Study 2), truth sensitivity was positively associated with cognitive reflection and actively open-minded thinking, and negatively associated with bullshit receptivity and conspiracy mentality. Although acceptance threshold and myside bias explained considerable variance in judgments of misinformation as true, neither showed robust associations with the measured individual-difference dimensions. The findings provide deeper insights into individual differences in misinformation susceptibility and uncover critical gaps in their scientific understanding.