Many people believe the personal attributes of trial participants substantially impact the decisions of juries, and considerable research has examined the extent to which characteristics of jurors and defendants are associated with juror judgments of guilt. To assess this broad issue, we meta-analyzed empirical studies examining the relationship between 11 juror and defendant characteristics and individual-level judgments of guilt in criminal trial contexts. Three potential moderator variables were also investigated: participant type, outcome type, and case type. In total, 464 effects were obtained from 272 published and unpublished studies. The 11 focal characteristics yielded sample-weighted mean correlations ranging from zero to .22 in magnitude, with the strongest overall relationships emerging for defendant socioeconomic status (Ϫ.11), defendant criminal record (.12), juror authoritarianism (.17), and juror trust in the legal system (.22). There was, however, substantial evidence of moderation for 10 of the 11 characteristics, suggesting their overall relationships vary according to one or more other variables. Moderator analyses revealed little support for participant type, some support for outcome type, and good support for case type with regard to their ability to explain variation in the observed effects. Overall, several juror and defendant characteristics were associated strongly enough with guilt judgments to warrant the attention of scholars and legal practitioners, and the results of this work add to our understanding of extralegal bias and juror decision making.