["Scandinavian Journal of Psychology, EarlyView. ", "\nABSTRACT\nChildhood bullying victimization experiences contribute to higher levels of loneliness in adulthood, but the mechanism underlying this relation is unclear. Potentially, individual differences in emotion regulation may underlie the relation between childhood bullying victimization and adult loneliness. The present study examined whether tendencies towards emotion suppression and rumination mediated the relation between retrospective bullying experiences and current loneliness in young adults. Undergraduate participants (N = 289, Mage = 19.09 years, SDage = 2.89 years) completed self‐reported questionnaires to assess retrospective bullying, tendencies towards the use of emotion suppression and rumination, and loneliness. We found significant direct effects of retrospective bullying victimization on the use of emotion suppression and rumination strategies, as well as direct effects of the tendency towards emotion suppression and rumination strategies on self‐reported adult loneliness. We found significant indirect effects of retrospective bullying experiences in predicting increased current loneliness through greater emotion suppression and through greater rumination. These results suggest that bullying victimization may be related to individuals' use of rumination and emotion suppression and subsequent increased loneliness in young adulthood. Future research should investigate methods of promoting non‐avoidance based emotion regulation strategies among individuals who experienced childhood bullying victimization to disrupt negative developmental trajectories leading to adverse psychosocial outcomes such as loneliness in adulthood.\n"]