Although the effects of group‐based victimhood on attitudes and emotions have been demonstrated in previous research, the ways it affects cognitive processes remain unclear. Four studies examined how a perpetual ingroup victimhood orientation (PIVO) affects cognitive biases. High levels of PIVO were associated with the categorization of more outgroups as hostile to the ingroup, and more rapid responses when using an enmity criterion (Study 1). PIVO was also associated with more attributions of malevolent intentions and fewer attributions of neutral intentions to outgroup members in ambiguous situations (Study 2a); when primed with reminders of historical group trauma, attribution of malevolent intentions increased among high‐ but not low‐ PIVO individuals (Study 2b). However, the effect extended to all participants when using a larger sample (Study 2c). The implications of these categorization and attributional biases are discussed in particular as regards the self‐perpetuating nature of perceived group victimhood.