Objective: Nocturia, defined as waking from sleep to void, is a frequent lower urinary tract symptom associated with impaired sleep quality and reduced quality of life. This study aimed to evaluate the prevalence of nocturia episodes and their impact on sleep disturbance and health-related quality of life. Methods: A questionnaire-based cross-sectional study was conducted at the Urology Outpatient Clinic of the General Hospital of Eastern Achaia between November 2023 and May 2024. Participants reporting nocturia were assessed using the Nocturia Quality of Life (N-QOL) questionnaire, the Athens Insomnia Scale (AIS), and the EQ-5D questionnaire. Demographic data and comorbid conditions were also collected. Univariate analyses and multiple linear regression were applied to identify factors associated with nocturia-related outcomes. Results: A total of 89 participants (78 men and 11 women; mean age 68.9 years) were included. Most participants reported 2–3 nocturnal voids per night. The N-QOL score was significantly associated with the frequency of nocturia episodes (r = −0.55, p < 0.0001), and regression analysis confirmed this relationship (coefficient: −6.7; 95% CI: −10.4 to −3.1). Individuals scoring ≥ 8 on the OAB-V8 scale demonstrated significantly lower N-QOL performance. Conclusions: Increasing nocturia frequency is associated with impaired sleep, reduced vitality, and diminished quality of life, particularly among older adults. Nocturia should be recognized as a clinically relevant symptom requiring targeted evaluation and personalized management strategies.