Hypoxia and tumor cell immunological escape greatly hinder the hepatocellular carcinoma (HCC) treatment efficiency. This study is designed to investigate the capability of carvacrol (CVR) to enhance sorafenib (SOR) anti-cancer efficacy and modulate anti-HCC immunity. CVR target and biological activities were predicted using Swiss Target Prediction website and PASS web server. UALCAN and LinkedOmics databases were used to examine hypoxia-inducible factor 1-alpha (HIF-1α) expression and the relationship between studied genes and tumor clinical features. Kaplan-Meier plotter (KM plotter) and TISIDB databases were used to illustrate correlation of HIF-1α with HCC prognosis and immune infiltration. The binding affinities of CVR to p300, KAT2B, CREBBP, and Hsp90 were demonstrated by molecular docking. In vivo analysis was performed in male Sprague-Dawley rats. The STAT3, JAK2, and fibrinogen-like protein 1 (FGL1) expressions were assessed by qRT-PCR. FGL1 was determined by ELISA. CD8+ T cell number was counted by flow cytometry. HIF-1α was determined by immunohistochemistry. CVR showed an HIF-1α inhibitory potential, which is highly expressed in HCC tissues. Also, elevated HIF-1α expression has been found to be correlated with clinicopathological characteristics, poor survival in HCC patients, and tumor immune cell infiltration. CVR/SOR enhanced liver functions and decreased AFP level. CVR/SOR hindered HCC progression by downregulating STAT3, JAK2, and FGL1. CVR/SOR induced tumor immunity via increasing CD8+ T cells. CVR/SOR is a powerful combination for tumor repression and enhancing SOR efficiency in HCC by modulating FGL1. Moreover, CVR/SOR might exert the aforementioned effects through HIF-1α/STAT3/FGL1 pathway.