Purpose: This study aimed to clarify the relationship between respiratory muscle strength and balance in older people requiring support or nursing care. Methods: Thirty-seven older subjects aged 65 years or older who were certified as requiring nursing care or support were included in the study. Maximal inspiratory pressure (PIMAX), maximal expiratory pressure (PEMAX), and one-leg standing time were measured. Additionally, the Functional Reach Test (FRT) was performed. Pearson correlation coefficient and multiple regression analyses were performed. Results: One-leg standing time was positively correlated with PEMAX, and was particularly correlated with PIMAX, while FRT score was not correlated with respiratory muscle strength. Multiple regression analysis with one-leg standing time as the dependent variable and PIMAX and PEMAX as independent variables showed that only PIMAX was significantly correlated with one-leg standing time. Conclusion: Focusing on expiratory and inspiratory muscle strength is important for improving one-leg standing ability and thus preventing falls in older people.