Numerous studies indicate an association between breastfeeding and decreased toddler adiposity. The mechanism behind this association is still unknown. One possibility is that children who are breastfed may have increased responsiveness to internal satiety cues. This study assessed the effect of satiety responsiveness on the association between breastfeeding and weight status among toddlers. We conducted a secondary analysis of data from 428 toddlers aged 2 years. Mothers' body mass index (BMI) and children's BMI z score were calculated from measured height and weight. Mothers completed a detailed breastfeeding survey and the satiety responsiveness subscale of the Child Eating Behaviour Questionnaire. Multiple linear regression and logistic regression were used to determine if satiety responsiveness mediated the effect of breastfeeding on BMI z score or overweight/obesity (BMI ≥ 85th percentile). Establishment of breastfeeding was associated with decreased BMI z score (0.40 vs. 0.60; p = 0.04), and increased breastfeeding intensity was associated with lower odds of overweight/obesity (OR 0.97, p = 0.04). Satiety responsiveness was not associated with either breastfeeding measures, suggesting it does not play a meditational role in the relationship between breastfeeding and toddler weight status. Furthermore, a relationship between satiety responsiveness and obesity does not exist after controlling for well-known confounders. This study did not find a mediation effect of satiety responsiveness on the association between breastfeeding and weight status in toddlers. More research is needed to characterize satiety responsiveness and its influence on the relationship between breastfeeding and childhood obesity.