Childhood inhibitory control (IC) is a key precursor of later social development, yet the mechanisms through which IC contributes to emerging interaction skills in toddlerhood remain insufficiently understood. We explored the cross-sectional associations between child IC and child interaction skills (responsiveness and involvement) with the mother at 30 months (N = 350) and conducted an exploratory longitudinal analysis of IC at 24 months and child interaction skills later at 30 months (N = 27) in mother–child dyads from the FinnBrain Birth Cohort Study. We measured IC using the Snack Delay task and child interaction skills with the mother using the Emotional Availability Scales. Higher IC was positively related to better child interaction skills with the mother cross-sectionally at 30 months, indicating a medium-sized effect. Our exploratory analysis also suggested a longitudinal association between 24 and 30 months. These findings suggest that early childhood IC is an important factor in children’s social interactions with mothers. More research is needed to explore the directionality of the associations. Replication studies are warranted.