Objective To examine the relationship between fundamental movement skills (FMS) and internalizing problems (depressive symptoms and anxiety symptoms) in early primary school children, as well as the mediating roles of self-esteem and self-efficacy.

Methods A stratified random sampling method was used to recruit 667 children (333 boys and 334 girls; mean age = 7.24 ± 0.71 years) from Grades 1 and 2 of primary schools in Shanghai, China. FMS were assessed using the Test of Gross Motor Development–Third Edition (TGMD-3). Mental health was assessed using the Chinese versions of the Children's Depression Inventory–Short Form (CDI-S), the Spence Children's Anxiety Scale–Short Version (SCAS-S), the Self-Esteem Scale (SES), and the General Self-Efficacy Scale (GSES). Differences between groups, partial correlations, and Bootstrap mediation analyses were conducted to explore the relationships among variables.

Results Object control skills were significantly negatively associated with depressive symptoms (β = −0.193, P < 0.001) and anxiety symptoms (β = −0.122, P < 0.01), and significantly positively associated with self-esteem (β = 0.104, P < 0.05). Self-esteem partially mediated the associations between object control skills and depressive symptoms (proportion mediated = 29.5%) as well as anxiety symptoms (proportion mediated = 32%). Locomotor skills were not significantly associated with depressive symptoms (β = −0.065, P > 0.05) or anxiety symptoms (β = −0.01, P > 0.05), and self-efficacy did not mediate any of the examined relationships.

Conclusions Higher levels of object control skills serve as a protective factor against depressive symptoms and anxiety symptoms in early primary school children, with part of the effect operating through enhanced self-esteem. Strengthening the learning and practice of object control skills during the early primary stage may help foster children's positive self-perceptions and improve all-round mental health.