This article explores the relationship between toddlers' (age: 30-33 months) well-being (WB), play (PL), social-emotional competence (SC) and movement skills (MS). Two hypotheses were put forward for testing: (1) there is a significant positive correlation between WB, PL, SC and MS, and (2) toddlers' WB can be predicted from their PL, SC and MS. The participants were 1084 children. The Early Years Movement Skills Checklist, and three categories from the observation material 'Alle Med' were used to assess WB, PL and SC. The results confirm the first hypothesis and partly the second. A strong positive correlation between SC, PL and WB may reflect how interweaved these variables are, and that observed play competence becomes important in the judgement of toddlers' social competence and well-being. Totally, 73% of the variance in WB was explained by the predictor variables PL and SC, while MS did not emerge as a unique predictor indicating that toddlers' well-being is primarily dependent on observation of children's play and social-emotional competence.