Our objectives were to examine the association between balance confidence, functional mobility measures, and the presence of disability in older adults in Saudi Arabia and to identify the optimal cutoff scores for these measures that predict disability. A cross-sectional study was conducted among 324 community-dwelling older adults (65 ± 7 years, 59% women). Disability was assessed using the Arabic version of the basic activities of daily living (ADLs) scale. Balance confidence was evaluated using the Arabic version of the Activities -Specific Balance Confidence (ABC) scale, and functional mobility was assessed using the 30-Second Chair Stand Test (30s-CST). The prevalence of disability was 33.6% among the participants. Logistic regression revealed a 6% increase in disability odds for each one-unit decrease in the 30s-CST (OR: 0.94) and a 3% increase per one-point decrease in the ABC score (OR: 0.97). The optimal cutoff scores were ≤5 repetitions for the 30s-CST (sensitivity: 74.4%; specificity: 51.4%; AUC: 0.64) and ≤40 for the ABC scale (sensitivity: 80.8%; specificity: 61.4%; AUC: 0.75). Impaired balance and functional mobility are significantly associated with disability among older adults. The 30s-CST and the ABC scale can be used as effective screening tools, but the cross-sectional design of the current study limits its generalizability. Longitudinal research is needed to validate these findings.