As people age, their motor and cognitive functions gradually decline. Changes in balance function may emerge as early as the prodromal phase of cognitive decline. This study aimed to explore differences in balance abilities among older adults with and without subjective cognitive decline (SCD). This cross-sectional study included 31 healthy controls (HCs) and 31 older adults with SCD. Cognition was assessed using the following measures: the Mini-Mental State Examination, the Montreal Cognitive Assessment Scale, the Memory and Executive Screening, the Verbal Fluency Test, the Rey Auditory Verbal Learning Test, the Boston Naming Test, and the Shape Trail Test A and B. The Berg Balance Scale (BBS), the Timed Up and Go test (TUGT), and a quantitative assessment of balance apparatus were used to assess balance functions in all subjects. The Statistical Package for Social Sciences version 27.0 was used to analyze differences between the two groups. Pearson’s correlation coefficients or Spearman’s rank correlation coefficients were used to explore the associations between balance and cognition. Compared to the HC group, the SCD group showed a significant increase in TUGT (p = 0.0004), with a lower BBS score (p < 0.0001). Additionally, older adults with SCD demonstrated a delayed latency of static balance parameters measured by a balance apparatus. The limit of stability significantly decreased (p < 0.0001), and the completion time of the limit of stability was prolonged in older adults with SCD (p = 0.002). Older adults with SCD demonstrated greater reductions in static balance and dynamic balance than HCs. Across both groups, poorer balance abilities were associated with poorer cognitive function. These findings indicate that balance impairments emerge as early as the SCD stage and correlate with early cognitive deterioration, highlighting the importance of incorporating balance assessments into routine clinical screening for populations at risk of dementia.