Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, currently impacts 1 in 3 adults, with projections that this will increase to 1 in 2 adults by 2040. In the absence of other hepatotoxins, MASLD begins with simple steatosis, which can progress to cirrhosis or hepatocellular carcinoma if left untreated. MASLD is an independent risk factor for type 2 diabetes (T2D), which equally promotes the progression of MASLD. While MASLD with T2D is associated with poor clinical outcomes, the hepatic adaptations of MALSD and T2D as discrete pathologies remain incompletely characterised. We generated T2D in male Sprague-Dawley rats by combining high-fat diet (HFD)-induced obesity with low-dose streptozotocin (STZ)-induced pancreatic insufficiency. We included treatment controls to delineate the contribution of HFD or STZ to the T2D liver. Histological quantification of microvesicular and macrovesicular steatosis was possible using digitised haematoxylin and eosin-stained rat liver sections and QuPath, which was complemented by quantitative proteomic analysis of liver specimens from matched animals using two-dimensional liquid chromatography tandem mass spectrometry. Histological assessment revealed that STZ-induced hyperglycaemia promoted hepatic microvesicular steatosis, while obesity and dyslipidaemia from HFD led to macrovesicular steatosis. In the combined HFD-STZ group, liver histology revealed fewer physiological hepatocytes, with evidence of mixed steatosis, showing a synergistic response to both treatments. Proteomics identified 1323 significantly altered (ANOVA, p<0.05; and z-Score log-2 fold change ±1.00) hepatic proteins across the four biological cohorts. Hierarchical clustering revealed that the synergistic impact of HFD and STZ dampened the impact of standalone STZ or HFD treatments. Pathway analysis revealed that proteins regulating ketone body and fatty acid metabolism were specifically altered in T2D. Enzymes that regulate mitochondrial beta-oxidation of fatty acids correlated with macrovesicular steatosis, while peroxisomal beta-oxidation was specific to microvesicular steatosis. Overall, we defined a hepatic signature that reflects both molecular and cellular adaptations to enhance our understanding of the MASLD-T2D link.