Background: Night eating behavior, adiposity, and poor sleep quality have been examined in previous studies, but additional evidence from large female samples with directly measured anthropometric characteristics is valuable. This study aimed to examine the associations among night eating behavior, body mass index (BMI), and subjective sleep quality in adult women, including their associations after adjustment for sociodemographic and lifestyle factors. Methods: This analytical cross-sectional study included 1203 women aged 18–65 years recruited from four family centers in Mamak, Ankara, Türkiye. Night eating behavior was assessed using the Night Eating Questionnaire (NEQ), and subjective sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Anthropometric measurements were obtained directly by the researcher. Correlation analyses and hierarchical multiple linear regression analyses were performed, with adjustment for age, education, occupation, smoking, alcohol consumption, and regular exercise. Results: The mean PSQI and NEQ total scores were 5.58 ± 2.84 and 12.50 ± 5.04, respectively. Night eating behavior was moderately positively correlated with PSQI scores (ρ = 0.404, p < 0.001), indicating poorer subjective sleep quality at higher NEQ scores. BMI showed weak positive correlations with PSQI scores (r = 0.122, p < 0.001) and NEQ scores (ρ = 0.085, p = 0.003). In the fully adjusted regression model, NEQ remained significantly associated with higher PSQI scores (β = 0.425, p < 0.001), whereas BMI was not significantly associated with PSQI scores (β = 0.051, p = 0.115). Older age and current smoking were associated with higher PSQI scores, while regular exercise was associated with lower scores. The final model explained 22.9% of the variance in PSQI scores (adjusted R² = 0.218). Conclusions: Night eating behavior was moderately associated with poorer subjective sleep quality and remained significantly associated with PSQI scores after adjustment for measured sociodemographic and lifestyle factors. Although BMI showed weak unadjusted associations with sleep quality and night eating behavior, its association with sleep quality was not statistically significant in the fully adjusted model. These findings highlight the relevance of night eating-related symptoms to subjective sleep quality in adult women, without establishing a causal relationship.