We conducted a systematic review to identify randomized controlled trials (RCTs) and single case research design (SCRD) studies of children with autism spectrum disorder that evaluate the effectiveness of responsivity intervention techniques for improving prelinguistic and/or language outcomes. Mean effect sizes were moderate and large for RCTs (33 studies; g = 0.36, 95% CI [0.21, 0.51]) and SCRD (34 studies; between-case standardized mean difference = 1.20, 95% CI [0.87, 1.54]) studies, respectively. Visual analysis (37 studies) revealed strong evidence of a functional relation for 45% of the opportunities and no evidence for 53%. Analyses of moderator effects and study quality are presented. Findings provide support for responsivity intervention strategies with more robust support for context-bound outcomes than more generalized outcomes.