Background: Pre-pregnancy excess weight is an important factor for adverse maternal perinatal outcomes; however, data for Greek women remain limited. Therefore, the aim of the present work was to evaluate the relation between pre-pregnant weight status and sociodemographic, anthropometric and lifestyle factors and maternal perinatal outcomes. Methods: In the present cross-sectional study, 5133 healthy women were enrolled from nine different Greek regions after applying specific inclusion and exclusion criteria. Validated questionnaires were used to assess the sociodemographic characteristics and certain lifestyle factors of the study population. Anthropometric and clinical data were retrieved from medical history files of the women, including measured weight in the first weeks of pregnancy and right before delivery, and maternal perinatal outcomes. Women’s weights and heights were also measured 2–5 years postpartum by trained nutritionists. Non-adjusted and adjusted statistical analysis was performed to assess whether pre-pregnancy weight status was associated with sociodemographic, anthropometric and lifestyle factors and maternal perinatal outcomes. Results: In pre-pregnancy, 17.5% of the women were overweight, and 4.9% were classified as obese. These rates were increased 2–5 years postpartum, reaching 21.0% for overweight and 9.6% for obese women. Pre-pregnancy overweight/obesity were associated with older maternal age, higher prevalence of overweight/obesity at 2–5 years postpartum and nonexclusive breastfeeding, as well as increased rates for preterm birth and pregnancy-induced hypertension after multiple adjustments. Conclusions: Overweight and obesity rates were high among women of childbearing age in Greece. These findings highlight the urgent need for healthy lifestyle promotion and targeted obesity prevention and intervention schemes among women of reproductive age.