This systematic review examined the compliance with the 24-h movement guidelines, and investigated its associations with health indicators for healthy children under 5 years of age. MEDLINE, PsycINFO, EMBASE, PubMed, Web of Science and SPORTDiscus were searched for peer-reviewed studies and the last search was conducted on 27 October 2020. The Newcastle–Ottawa Scales were used to assess the quality of included studies. Eighteen articles including 8,943 participants from 11 countries were included. On average around 13% of the children met all three guidelines. Meta-analyses of the associations between meeting all three guidelines and adiposity yielded no significant results (r =–0.03; 95% CI =–0.12, 0.06; I 2 = 51%; P = 0.48). Meeting more guidelines was associated with better psychosocial health (3/4 studies). Associations between meeting individual or combined guidelines and motor development yielded mixed results (2/2 studies), while no associations between meeting guidelines and cognitive development were observed (1 study). Compliance with all three guidelines was low. Further evidence is required to understand the associations between meeting the 24-h movement guidelines and health outcomes. Nevertheless, there was evidence of a dose-response relationship between meeting the guidelines and better psychosocial health in the early years.