Twenty-six key odourants were found in Hongxin and Shatian pomelo peel oils using aroma extraction dilution analysis (AEDA). trans-2-Dodecenal was identified to be the most potent key odourant, with a flavour dilution value of 100000 in Hongxin and 10000 in Shatian. Hongxin peel oil was found to be more floral while Shatian was green and peely. Gas chromatography coupled with quadrupole time-of-flight mass spectrometry (GC-QTOF/MS) revealed 22 volatiles that were undetected by the less sensitive GC-MS detector. Non-volatile compounds in the peel oils were identified and quantified using liquid chromatography (LC)-QTOF/MS. Besides organic acids, naringin and bergamottin were, concentration-wise, the dominant non-volatile compounds identified in the juices and peel oils, respectively. Pomelo juices had higher antioxidant capacities than their peel oils, and Shatian pomelos possessed higher antioxidant activities than Hongxin. The use of high-resolution detectors allowed for improved compound detection and identification in citrus, and may be applied to other complex natural products.