Background: Diabetes mellitus (DM) is a chronic disease afflicting people of all races, sex, economic and social status, and of all ages. Obesity is a major contributor to the type 2 diabetes epidemic. Obesity in persons with diabetes is associated with poorer control of blood glucose levels, blood pressure, and cholesterol, placing patients at higher risk for both cardiovascular and microvascular disease. Aim: To determine the prevalence of obesity and the associated risk factors among diabetic patients in Bowen University Teaching Hospital (BUTH), Ogbomoso. Materials and Methods: The study was a descriptive cross-sectional study. The data collection lasted 4 months between March and June 2018. A pretested questionnaire was used to collect data on socio-demographic characteristics and medical history of participants. We measured and recorded blood pressure, weight and height of each of the participants. The data collected were analyzed using SPSS for Windows version 20 statistical software package. The association between categorical variables were tested using Chi-square. Data presentation was done using tables, frequencies and percentages. Results: Two hundred and seventy-five participants were recruited for this study. Their age ranges from 28 years to 85 years with the mean age of 59.07±11.82 years. Obesity was found in 29.8% of the study participants.  Obesity was found to be associated with age group, sex, marital status, educational level, duration of diagnosis of diabetes and hypertension. The association was statistically significant. Conclusion: The prevalence of obesity in type 2 diabetes was high in this study and was associated with age group, sex, marital status, educational level, duration of diagnosis of diabetes and level of blood pressure.  There is a need to intensify effort to control obesity and achieve optimal blood pressure control among diabetic patients and prevent complications from ensuing.