Objective Diabetes mellitus (DM) is one of the most common chronic diseases in the world. Diabetes mellitus has a major effect on patients’ quality of life, especially when the patient has other comorbidities. Therefore, this study aims to assess the quality of life of type 2 diabetic patients in the Al-Ahsa region of Saudi Arabia. Methods This was a cross-sectional study, which was conducted from September 2020 to May 2021 on patients with type 2 diabetes mellitus in the Al-Ahsa region of Saudi Arabia. Inclusion criteria were patients diagnosed with T2DM and aged 18 years and older. The EQ-5D-5L tool was used in this study to measure the quality of life. Results A total of 321 patients with T2DM participated in the study. Only 8.4% of the study participants reported that their disease did not let them do their daily activities at all. The most commonly reported problems related to diabetes mellitus and its effect on patients’ quality of life were pain/discomfort (around 68.0% of the patients reported some sort of problems in this dimension), followed by mobility, and depression and anxiety. There was a significant difference between males and females in terms of their quality of life, specifically self-care, pain and discomfort, and depression and anxiety (p<0.05). Patients from different marital statuses, education levels, employment status, and duration of the disease showed a significant difference in quality of life, except for depression and anxiety (p>0.05). Conclusion Pain/discomfort, mobility, and depression/anxiety are the main problems that are affecting diabetic patients’ quality of life. Future studies are recommended to explore the effectiveness of patient tailored interventions to decrease the negative impact of these dimensions on patients’ quality of life.