Major depressive disorder (MDD) is a debilitating illness, which is widely prevalent. There is a need to elucidate MDD pathophysiology to better target treatment. Studies have shown association between hippocampal subfield volumes and MDD, making the subfields potential biomarkers. We use high-resolution 7T-MRI to perform effective subfield delineations and evaluate subfield volume differences between sixteen patients and sixteen controls. Using automatic segmentation of hippocampal subfields software revealed a trend towards reduced right-CA1 and right-DG subfield volumes in patients compared to controls. Identifying hippocampal subfield volumes as imaging biomarkers for MDD may help design more targeted treatments for the disease.