O-linked-β-N-acetylglucosamine (O-GlcNAc) modified proteins are critical in myriad cellular processes and functions. Abnormal O-GlcNAcylation is associated with a spectrum of diseases, including Alzheimer’s disease, cancer, cardiovascular disease, and diabetes. Mitochondrial protein O-GlcNAcylation is emerging as a key regulator of cellular energetic metabolism, redox signaling and cell survival pathways, but the mechanisms involved are largely unknown. O-GlcNAc transferase (OGT) is the enzyme responsible for the addition of O-GlcNAc to target proteins while O-GlcNAcase (OGA) catalyzes the removal of the modification from target proteins. OGT and OGA are encoded by single genes in C. elegans (ogt-1 and oga-1, respectively). Null alleles of ogt-1 and oga-1 are viable and fertile, unlike knockouts of OGT in mouse that result in embryonic lethality. We hypothesize that O-GlcNAc cycling mediated by OGT and O-GlcNAcase play a role in regulating mitochondrial metabolism and morphology. To that end, we measured oxygen consumption rate (OCR), a proxy for mitochondrial oxidative phosphorylation function, in N2, ogt-1 and oga-1 null mutants. OCR was measured using the Seahorse Bioscience XFe 24 Extracellular Flux Analyzer and normalized by number of worms for each individual well. Our results suggest that altered O-GlcNAc cycling reduces oxygen consumption by negatively impacting mitochondrial oxidative metabolism. It is still unknown if these reductions in OCR are caused by reduction in mitochondria content or reduced mitochondrial function. These results will add to the knowledge of how O-GlcNAcylation modulates mitochondrial health and function.