Purpose: This study aimed to evaluate the health behaviors and nutritional characteristics of obese and morbidly obese older adults using the 2022 Korea National Health and Nutrition Survey (KNHANES). Methods: This study analyzed the data of 1,837 older adults aged 65 years or older who participated in KNHANES. Data included demographic characteristics, body mass index (BMI), Generalized Anxiety Disorder-7 (GAD-7), subjective health status, weight change over the past year, weight control attempts, diet therapy, physical exercise, and nutrients intake. Obesity was defined as BMI ≥ 25 kg/m2, and morbid obesity as BMI ≥ 30 kg/m2. Results: A total of 643 participants (BMI ≥ 25 kg/m2) were included, 570 of whom were classified as obese and 73 into morbidly obese group. Prevalence of hypertension was significantly higher in morbidly obese group (82.2%) compared with obese group (66.8%). There were no significant differences in GDA-7, activity limitations, or subjective health status between the two groups. Physical activity and resistance exercise were less than 20% in both groups, and were less frequent in morbidly obese group than in obese group. Additionally, regardless of weight loss, the morbidly obese group had greater weight gain than the obese group. Although the nutrient intakes of the two groups were similar, there appeared to be nutritional imbalances. Conclusion: Obesity old adults have poor health behaviors, but the morbidly obese group is particularly vulnerable. Obese older adults have poor health behaviors, but those who are morbidly obese are particularly vulnerable. Therefore, active efforts are needed to monitor people with poor health behaviors in the morbidly obese group and to improve their health.