There exists a pressing need for a non-invasive panel that differentiates mild fibrosis from non-fibrosis in metabolic dysfunction-associated steatotic liver disease (MASLD). In this work, we applied quantitative lipidomics and sterolomics on sera from the PERSONS cohort with biopsy-based histological assessment of liver pathology. We trained a lasso regression model using quantitative omics data and clinical variables, deriving a combinatorial panel of lipids and clinical indices that differentiates mild fibrosis (>F1, n   = 324) from non-fibrosis (F0, n   = 195), with an area under receiver operating characteristic curve (AUROC) at 0.775 (95% confidence interval [CI]: 0.735 0.816). Circulating sulfatides (SLs) emerged as central lipids distinctly associated with fibrosis pathogenesis in MASLD. Lipidomics analysis of lipoprotein fractions revealed a redistribution of circulating SLs from high-density lipoproteins (HDLs) onto low-density lipoproteins (LDLs) in MASLD fibrosis. We further verified that patient LDLs with reduced SL content triggered a smaller activation of type II natural killer T lymphocytes, compared with control LDLs. Our results suggest that hepatic crosstalk with systemic immunity mediated by lipoprotein metabolism underlies fibrosis progression at early-stage MASLD.