Motivation is a proximal determinant of behavior in many psychological theories, and increasing motivation is central to most behavior change interventions. This systematic review and meta-analysis sought to fill a gap in the literature by identifying features of behavior change interventions associated with favorable changes in three prominent motivational constructs: intention, stage of change and autonomous motivation. A systematic literature search identified 88 intervention studies (N = 18,804) which assessed changes in at least one of these motivational constructs for physical activity (PA). Intervention descriptions were coded for potential moderators, including behavior change techniques (BCTs), modes of delivery and theory use. Random effects comparative subgroup analyses identified 19 BCTs and 12 modes of delivery associated with changes in at least one motivational outcome. Interventions which were delivered face-to-face or in gym settings, or which included the BCTs problem solving, self-monitoring of behavior or behavioral practice/rehearsal, or which included the combination of self-monitoring of behavior with any other BCTs derived from control theory, were all associated with beneficial changes in multiple motivational constructs. Meta-regression analyses indicated that increases in intention and stage of change, but not autonomous motivation, were related to increases in PA. The intervention characteristics identified here as effective in changing motivation seemed to form clusters related to behavioral experience and self-regulation, which have previously been linked to changes in behavior as well. These BCTs and modes of delivery merit further systematic study, and could be used as a foundation for improving interventions targeting increases in motivation for PA.