Sleep complaints are common amongst mothers of infants and insufficient, inefficient or fragmented sleep is associated with postnatal depression. The aim of this review is to determine whether psychosocial sleep-focused interventions offered in the perinatal period improve infant sleep or maternal mood. We searched PubMed, PsycInfo, EMBASE and CINAHL with no date restriction. We reviewed 1097 articles, resulting in nine papers (n = 1,656) that fit the eligibility criteria for inclusion in the analyses. The primary outcome was infant sleep, defined as maternal reports of infant nocturnal total sleep time and number of night-time wakes. The secondary outcome was maternal mood. The meta-analysis indicated improvements in reported infant nocturnal total sleep time (Hedge's g = 0.204, p < 0.01). However, there was no evidence for reducing infant night wakes (Hedge's g = 0.103, p = 0.134). There was evidence of maternal mood improvements (Hedge's g = 0.152, p = 0.014), however, this could have been influenced by publication bias. Psychosocial sleep interventions appear to impact the amount of sleep that a mother reports her baby to have, although the infants continue to wake as frequently. More research is needed to confirm whether sleep-related improvements can translate into improvements in maternal mood.