Research has highlighted the role of dissociation in understanding the trauma–psychosis relationship. Moreover, it has been proposed that the association between trauma and psychotic symptoms may be both directly and indirectly explained by dissociative processes. The current study sought to investigate the relationship between age at first sexual trauma, dissociative experiences and psychotic‐like experiences (PLEs) in 269 female trauma survivors (overall mean age = 32.11, SD = 10.55). Mediation analyses were employed to estimate the direct effects of childhood sexual abuse (CSA; mean age at abuse onset = 6.53, SD = 3.98) and adult sexual assault (ASA; mean age at abuse onset = 18.72, SD = 2.59) on PLEs, and the indirect effects via the three subscales of absorption, depersonalisation and amnesia. The findings showed that the CSA group was significantly associated with each of the three dissociation variables (p < 0.01 for each variable), while the ASA group was significantly associated with absorption and depersonalisation (p < 0.01 for each variable). Depersonalisation partially mediated the effect between CSA and PLEs, whereas the relationship between ASA and PLEs was fully mediated via depersonalisation. The findings are consistent with, and complement, models implicating depersonalisation as a unique mechanism in the pathways between sexually based victimisation and PLEs.Key Practitioner Messages CSA and ASA have both direct and indirect impacts on later psychological symptoms. Elucidating mechanisms by which sexual trauma leads to the transition to PLEs should be instrumental in treatment formulation. Depersonalisation is a complementary mechanism in the link between sexually based trauma and PLEs. Evaluating dysfunctional metacognitive beliefs is crucial for therapeutic intervention as these may contribute to the development and maintenance of symptoms. ‘Investigate[s] the relationship between age at first sexual trauma, dissociative experiences and psychotic‐like experiences… in 269 female trauma survivors’