This study explores the relationship between parental attitudes toward outdoor activities and children’s health-related quality of life, focusing on the mediation of outdoor activity time and nature connections. Data from 399 kindergarten children, supplemented by parental insights, were analyzed using structural equation modelling (SEM). Positive parental attitudes toward outdoor activities were found to predict enhanced physical functioning and kindergarten performance. Additionally, a positive correlation was observed for social functioning, while emotional functioning remained unaffected. Parental attitudes directly influenced physical functioning, with indirect effects on kindergarten performance mediated by outdoor time and nature connections. These findings highlight the importance of parental attitudes in promoting children’s well-being and suggest potential strategies to enhance their health-related quality of life.