In the present study, we examined sleep complaints in postpartum women with a past history of childhood trauma relative to postpartum women who were not exposed to childhood trauma. We also assessed whether sleep was differentially affected by the type of childhood trauma experienced and the relative contribution of posttraumatic stress disorder. Participants completed questionnaires related to mental health over the phone at four months postpartum (n = 173). We found that after adjusting for covariates, participants who reported childhood neglect or physical abuse (regardless of sexual abuse) were significantly more likely to endorse difficulty falling asleep and staying asleep relative to participants who were not exposed to childhood trauma. Furthermore, PTSD was associated with sleep problems, such that mothers with childhood trauma who had recovered from a past history of PTSD were more likely to have difficulty falling and staying asleep than mothers who were exposed to childhood trauma but never developed PTSD, while mothers with persistent PTSD were at the highest risk for reporting sleep problems. Our findings affirm the contribution of childhood trauma and PTSD to postpartum sleep problems, and suggest that sleep may be disturbed in the postpartum even in women who have recovered from PTSD.