Introduction and Hypothesis: This study is aimed at comparing the effects of different external electrical stimulation (ES) applications on bladder functions, symptom severity, quality of life and perception of subjective improvement (PSI) in women with overactive bladder (OAB). Methods: Women were randomly allocated into the control group (lifestyle advice, n = 24), neuromuscular electrical stimulation (NMES; NMES + lifestyle advice, n = 22), and transcutaneous electrical nerve stimulation (TENS; TENS + lifestyle advice, n = 21). NMES or TENS was applied to the groups 3 days a week for 6 weeks. Bladder function was evaluated with a 3-day bladder diary, the symptom severity with Overactive Bladder Questionnaire-Version 8 (OAB-V8), quality of life with the King’s Health Questionnaire (KHQ), and PSI with the Likert type-scale. Results: After treatment, both treatment groups showed improvement in bladder function as well as a decrease in OAB-V8 and KHQ scores (p < 0.05). In the intergroup comparison, there was a decrease in voids/day, general health, and physical limitation scores of the KHQ in the NMES group compared with the TENS group (p < 0.05). In terms of PSI, there was a significant difference between the NMES and TENS groups in favor of the NMES group (p < 0.05). Conclusions: Neuromuscular electrical stimulation and TENS were associated with improvements in bladder function, OAB symptoms, quality of life, and PSI levels in women with OAB. Greater improvements over time in bladder function, quality of life, and PSI levels were observed in the NMES group than in the TENS group. Accordingly, NMES may be associated with larger symptom and quality-of-life improvements.