Background <p>Given the high prevalence of physical and mobility disabilities among older adults worldwide, and their impact on both mental and physical health, understanding the factors associated with quality of life in this population is essential. This study aimed to determine the relationship between general self-efficacy and quality of life among older adults with physical/mobility disabilities.</p> Methods <p>This cross-sectional study was conducted in 2020 on 200 older adults with physical and mobility disabilities referred to selected educational and medical centers affiliated with Babol University of Medical Sciences, using quota sampling. Data were collected using the Abbreviated Mental Test (AMT), demographic questionnaire, the World Health Organization Quality of Life-BREF (WHOQOL-BREF), and the 10-item General Self-Efficacy Scale (GSE-10). Data were analyzed using SPSS version 20, employing Pearson correlation and linear regression, with the significance level set at <i>p</i> &lt; 0.05.</p> Results <p>There was a direct and significant relationship between general self-efficacy and overall quality of life, as well as all its domains. General self-efficacy accounted for 35% of the variance in overall quality of life among the participants. Specifically, for every 1.95-unit increase in general self-efficacy, the overall quality of life score increased by 1 unit. Moreover, multivariable linear regression analysis indicated that self-efficacy remained a strong and statistically significant predictor of overall quality of life after adjusting for age, gender, education, income, and the presence of chronic illnesses (comorbidity) (β = 1.166, 95% CI: 0.936–1.397, <i>p</i> &lt; .001).</p> Conclusions <p>Enhancing self-efficacy may play a pivotal role in improving the quality of life among older adults with physical or mobility disabilities. Future longitudinal and qualitative studies are warranted to guide the design of tailored and culturally appropriate interventions.</p>