Having everyone on the "same page" in teams working toward a common objective is essential to effective teamwork, yet an integrative understanding of factors that enhance these shared mental models (SMM) is absent from the evidence base. We addressed this gap in the literature via a prospectively registered (https://bit.ly/2I7zJzz) systematic review of five databases to identify eligible studies and statistically synthesize evidence from 36 lab or field experiments (131 effect sizes, N participants = 6,209, N teams = 1,912) that tested the effectiveness of team development interventions (TDI) for enhancing SMM among adults where participants were randomized to experimental groups. Via a three-level random effects meta-analysis, we found a positive and significant medium-to-large overall effect of TDI on SMM, g = .61, 95% CI [.41, .82]; sensitivity and meta-bias analyses (e.g., risk of bias, Grading of Recommendations, Assessment, Development and Evaluations [GRADE] assessment) generally supported the robustness of this overall effect. Moderator analyses indicated that outcome assessment method meaningfully altered the overall pooled effect, with stronger effects observed when outcomes were researcher-assessed. Nevertheless, our assessment indicated low certainty in the quality of the evidence and "noisiness" in the overall estimate (i.e., prediction interval of −0.66 and 1.89). Overall, this study contributes new knowledge on the antecedents of SMM that can inform theory regarding the nomological network of this concept, as well as methodological insights that can improve the evidence-base in future work.