Background: The geriatric oncology population is uniquely vulnerable to increased levels of psychological distress due to age related challenges such as social isolation, change in lifestyle, and comorbid conditions. In the general population, higher levels of psychological distress have been shown to impact treatment course, quality of life, and survival. The NCCN Distress Thermometer (DT) is a validated fast and effective screening tool for psychological distress, with a cutoff score of 4 yielding optimal sensitivity and specificity in a general cancer population. However, the best cutoff for detecting psychological morbidity in older cancer patients is unclear. In this study, we aim to compare the sensitivity and specificity of various cutoff values for the Distress Thermometer score to predict Geriatric Depression Scale (GDS) score. Methods: Data is derived from 242 geriatric oncology patients from the Senior Adult Oncology Center at Jefferson Health. Using a cutoff of 5 for the GDS as the clinical standard guideline, we use receiver operating characteristic (ROC) curve analysis of the univariable logistic regression model to predict clinical depression. Results: A cutoff DT score of 3.5 was found to be most sensitive and specific (0.66,0.68) for predicting clinical depression (Area Under the ROC Curve (AUC) = 0.70). Multivariable logistic regression including age improved the predictive ability of the DT score to an AUC of 0.75. Conclusions: The increase in AUC with the addition of age indicates the potential use of a composite value of age and DT score to best determine at-risk patients in a clinical setting. While these results indicate the utility of the Distress Thermometer as an effective screening tool in the geriatric oncology population, our findings also suggest that a lower threshold score is advised for clinicians who are hoping to identify older cancer patients who are distressed. Patients who meet the threshold criteria would then be assessed further for triage into appropriate levels of geriatric supportive services.