Background Obesity in Saudi Arabia is on the rise, especially among females who are more likely to suffer from obesity in the reproductive age group than males in the adult age group. Biologically, pregnancy can increase women’s weight and put them at greater risk for adverse obstetric outcomes. Objectives To find the prevalence of obesity among pregnant women and their obstetric outcomes. Methods This retrospective study was conducted on pregnant women who delivered between January 2013 and May 2018 at the obstetrics clinic of King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. A datasheet was formed to collect data from the medical records of these pregnant women. The analysis was done using the Statistical Package for Social Sciences (SPSS), version 26 (IBM SPSS Statistics, Armonk, NY). A p-value of < 0.05 was used to calculate statistical significance. Results A total of 9,095 pregnant women delivered during that period. Of those women, a total of 2,235 were found to be obese, and 1,842 were included in the study. A total of 1,130 women were categorized under Class I obesity, 458 were categorized under Class II obesity, and 254 were categorized under Class III obesity. The majority of the sample were Saudis (72.3%) and young adults (90.8%) with 1,672 cases. The average age was 31.7 (standard deviation (SD): 5.9). Twenty percent of the sample had preterm newborns, while the majority (62.4%) ended up with cesarean delivery. Advanced age, multipara, and cesarean delivery were statistically significant with adverse pregnancy outcomes (p < 0.05). Conclusion As demonstrated in this study, obesity among females in Saudi Arabia has increased over the past decade. Hence, this puts them at higher risk of developing adverse pregnancy outcomes, as pregnancy physiologically results in additional weight gain. Proper antenatal counseling, health education, and a comprehensive plan prior to conception are highly recommended.