<p>Life adjustment strategies are essential for maintaining mental and emotional well-being and fostering resilience, particularly during middle adulthood. This study aimed to examine the associations between occupational balance, physical activity, and life adjustment strategies among middle-aged adults. A cross-sectional, community-based study was conducted between February and August 2024, enrolling adults aged 40–60 years (<i>n</i> = 1120) across eight representative provinces in Thailand. Data were collected on life adjustment strategies, occupational balance (OB), physical activity (PA), and socio-demographic characteristics. Hierarchical linear regression was employed to analyze the incremental predictive power of demographics, OB, and PA on life adjustment strategies. The final regression model explained 23.4% of the total variance. Socio-demographic analysis revealed that participants aged 55–60 and those who were self-employed reported significantly higher adjustment scores. In Model I, occupation was a primary predictor (β = 0.665, <i>p-</i>value &lt; 0.001). The addition of occupational balance in Model II significantly improved the model (Δ R²= 0.183, <i>p-</i>value &lt; 0.001), with time balance (β = 0.803, <i>p-</i>value &lt; 0.001), resting balance (β = 0.245, <i>p-</i>value &lt; 0.01), and amount balance (β = 0.278, <i>p-</i>value &lt; 0.01) showing strong positive correlations. In Model III, sedentary behavior was significantly and negatively associated with life adjustment strategies (β = − 0.255, <i>p-</i>value &lt; 0.001). These findings underscore the critical role of occupational balance, specifically the management of time and rest in supporting life adjustment.</p>