This study aimed to examine associations of dietary quality and diversity among reproductive-aged women with overweight and obesity. We conducted a cross-sectional study in the Health and Demographic Surveillance System of the Dar es Salaam Urban Cohort Study (DUCS) in Tanzania. A random sample of 1004 non-pregnant women was selected from the DUCS population database and interviewed about dietary information using the FFQ. Women were aged 30.2 (±8.1) years; 27.8% were overweight and 22.6% were obese. All 1004 women in the study consumed starchy staple foods. Of all the women studied, 10.5%, 1.7% and 3.8% consumed vitamin A rich dark green vegetables, nuts and seeds, and beans and peas, respectively. Compared with women in the lowest quintile of Prime Dietary Quality Score (PDQS), those who were in the highest quintile were significantly less likely to be overweight or obese (Adjusted Prevalence Ratio (APR) = 0.76, 95%CI: 0.62, 0.89) (F for trend = 0.029). Dietary diversity score (DDS) was not significantly associated with overweight and obesity. Risk factors included the highest consumption of animal foods (APR = 2.81, 95% CI: 1.51-3.51) and fast food (APR = 2.57, 95% CI: 1.24-4.34). Consumption of legumes and whole grains was associated with lower risk (APR = 0.59; 95% CI: 0.38-0.2). Dietary quality is an important predictor of overweight and obesity among women of reproductive age. Nutrition interventions may be warranted to support women of reproductive age to enter pregnancy with healthier weight to prevent adverse pregnancy outcomes and future risk of chronic diseases.