Obesity is associated with chronic low-grade adipose tissue inflammation, leading to insulin resistance. Inflammation associated with insulin resistance is an interesting area of biomedical research and is expected to affect insulin signaling pathways via the downregulation of glucose transporters. In the present study, we investigated the inhibitory effects of Maclura tricuspidata fruit vinegar (MFV) against TNF-α-induced inflammation and insulin resistance in 3T3-L1 adipocytes. Differentiated 3T3-L1 adipocytes were pretreated with MFV at various concentrations and then cultured with TNF-α to induce insulin resistance. Then, lipid droplets, inflammatory cytokine and glucose uptake, PPARγ and GLUT4 expression, and IRS-1 phosphorylation were analyzed. MFV attenuated the TNF-α-induced decrease in lipid droplets and glucose uptake and inhibited TNF-α-induced inflammatory cytokine, IL-6, and MCP-1 production. MFV reversed the decrease in adiponectin produced by TNF-α. Furthermore, MFV upregulated the TNF-α-induced suppression of PPARγ and GLUT4 protein expression and reduced the TNF-α-induced phosphorylation of IRS-1. These findings suggest that MFV effectively ameliorates TNF-α-induced insulin resistance; accordingly, we recommend the use of MFV for the control and management of insulin resistance and its associated complications.