Shared book reading is thought to have a positive impact on young children’s language development, with shared reading interventions often run in an attempt to boost children’s language skills. However, despite the volume of research in this area, a number of issues remain outstanding. The current meta-analysis explored whether shared reading interventions are equally effective (a) across a range of study designs; (b) across a range of different outcome variables; and (c) for children from different SES groups. It also explored the potentially moderating effects of intervention duration, child age, use of dialogic reading techniques, person delivering the intervention and mode of intervention delivery. Our results show that, while there is an effect of shared reading on language development, this effect is smaller than reported in previous meta-analyses (g = 0.215, p < .001). They also show that this effect is moderated by the type of control group used and is negligible in studies with active control groups (g = 0.021, p = .783). Finally, they show no significant effects of differences in outcome variable (ps = .400), socio-economic status (p = .654), or any of our other potential moderators (ps = .103), and non-significant effects for studies with follow-ups (g = 0.145, p = .070). On the basis of these results, we make a number of recommendations for researchers and educators about the design and implementation of future shared reading interventions.