Triacylglycerols (TGs) serve critical cellular functions as both energy reserves and reservoirs of fatty acid (FA) building blocks for membrane phospholipids. Both the identity of the fatty acid and their stereo-specific numbering (sn-) position on the glycerol backbone of TGs are critical in understanding their biological functions. Advancement of this understanding has been impeded by the complex array of lipids present in nature and the limitations of contemporary lipidomic technologies to resolve and structurally discriminate between TG regioisomers. Here, we introduce ion mobility-aligned collision-(CID)/ozone- (OzID) induced dissociation for detailed TG structural analysis on liquid chromatography timescales. While MSn approaches based on varying combinations of collision- (CID), ozone- (OzID) and photo- (PD) dissociation have been demonstrated to achieve isomeric-discrimination of TGs, these are most-often characterised by low duty cycle and thus an incompatibility with high-throughput analysis of complex lipidomes. We have enabled CID/OzID as a pseudo-MS3 sequence on a traveling-wave ion-mobility mass spectrometer. In this approach, mass-selected [TG+Na]+ precursor ions are subjected to CID in the pre-mobility trap, with the resulting product ions separated in the mobility region prior to OzID in the post-mobility transfer array. Extraction of the resulting data in the mobility-time domain enables assembly of OzID mass spectra of individual CID product ions and consequent assignment of both fatty acyl-chain identity and sn-position in a single composite acquisition achieved on the native duty cycle of the instrument. In application of this sequence to isomeric reference standards of both AAB- and ABC-type TGs (e.g., TG 16:0_16:0_18:1 and TG 16:0_18:0_18:1, respectively) diagnostic CID/OzID product ions were observed that uniquely identify the position of each acyl chain on the glycerol backbone and thus enable discrimination between isomers even where chromatographic resolution is incomplete.