In this note, we provide direct evidence of cheating in online assessments of political knowledge. We combine survey responses with web tracking data of a German and a U.S. online panel to assess whether people turn to external sources for answers. We observe item-level prevalence rates of cheating that range from 0 to 12% depending on question type and difficulty, and find that 23% of respondents engage in cheating at least once across waves. In the U.S. panel, which employed a commitment pledge, we observe cheating behavior among less than 1% of respondents. We find robust respondent- and item-level characteristics associated with cheating. However, item-level instances of cheating are rare events; as such, they are difficult to predict and correct for without tracking data. Even so, our analyses comparing naive and cheating-corrected measures of political knowledge provide evidence that cheating does not substantially distort inferences.