Justice in the early nineteenth-century Irish court was shaped by the bodies of men. Physical appearance was understood to provide information about a person's social background, character, sense of guilt, and honesty; it was available to be read by others in the court when interpreting events during trial. As well as making judgements based on clothing and the appearance of the body, how court actors performed emotion was central to discussions of how their bodies, and so their character, should be read. Such readings of emotion on the male body were heavily shaped by the science of physiognomy that provided a model for interpreting often complex, ambiguous, and individualized displays of emotion. This article uses evidence provided in newspaper reporting of criminal trials in early nineteenth-century Ireland to explore how performances of emotion were used and interpreted as a form of evidence in the courtroom. It demonstrates that emotion and "emotional dispositions" were central to determining a man's character, affecting how their evidence was viewed and whether they received justice. As importantly, displays of emotion in court were involved in the shaping of courtroom dynamics. In both cases, emotion became implicated in the making of justice.