<p>Cells produce metabolic intermediates through catalytic reactions, mainly via post-translational modifications. The modification of proteins by O-linked N-acetylglucosamine, known as O-GlcNAcylation, is one of the most common post-translational modifications. As O-GlcNAcylation and phosphorylation can occur at serine or threonine residues, it is crucial that the interplay between these two modifications is vital to bioenergetic and biosynthetic demand. Although emerging recognition linking O-GlcNAc modification and phosphorylation to protein functions has been obtained, the issue of how altered O-GlcNAcylation or phosphorylation regulates each other in the metabolic system remains uncertain. The combination of cell biological and proteomic approaches over the recent few years has not only highlighted the interactions between O-GlcNAcylation and phosphorylation in protein function but also prompted us to elucidate the underlying mechanisms behind this crosstalk controlling metabolic homeostasis. The purpose of this review is to summarize recent advances in the O-GlcNAcylation/phosphorylation regulation of the metabolic process. An extensive exploration of this interplay has significant implications for metabolic control systems, including glucose, lipid, and nucleotide metabolism, where dysregulation in O-GlcNAcylation and phosphorylation of metabolic syndrome is essential.</p>