Lipoproteins are biochemical complexes of apolipoproteins and lipids that primarily mediate the transport of lipids through the circulation, from sites of absorption or synthesis to those of use, storage, or excretion. In type 2 diabetes (T2D), disruptions in lipoprotein metabolism are key drivers of complications and strongly contribute to atherosclerotic cardiovascular disease (ASCVD). As a result, ASCVD remains the leading cause of death in T2D, with significantly higher prevalence than in non-diabetic individuals. Protein post-translational modifications (PTMs) have emerged as key contributors to organ failure mechanisms, with specific PTMs closely linked to the pathogenesis of T2D. Several reports also emphasized the value of plasma apolipoproteins for the early prediction of ASCVD in cardiometabolic diseases. Thus, apolipoproteins, and especially their structurally post-translational modified forms, offer new insights into the molecular mechanisms of lipoprotein dysfunction and may enhance the specificity of ASCVD risk stratification in T2D. This review outlines major apolipoprotein PTMs identified in T2D, many of which can now be quantified in biological samples, particularly via mass spectrometry. We also discuss their role in lipoprotein metabolism dysfunction and their potential value in assessing ASCVD risk in T2D, highlighting their growing potential as clinical biomarkers in population-based cohort studies.