Background/Objectives: Xanthoceras sorbifolium oil (XSO), containing nervonic acid and unsaturated fatty acids (93%), exhibits lipid-lowering potential; yet, its mechanisms involving gut–liver crosstalk remain unclear. This study investigated XSO’s anti-hyperlipidemic effects and gut microbiota interactions. Methods: Forty-eight Sprague Dawley male rats were divided into: normal control (NC), high-fat diet (HFD), XSO prevention (XOP, 1.4 mL/kg pre-HFD), and XSO treatment (XOT, post-HFD). Serum lipids, fecal short-chain fatty acids (SCFAs), gut microbiota (16S rRNA), and lipidomics (UPLC-MS/MS) were analyzed after 12 weeks. Results: XOP significantly reduced serum total cholesterol (TC, 26.8%), triglycerides (TG, 35.9%), and low-density lipoprotein cholesterol (LDL-C, 45.9%) versus HFD (p < 0.05), while increasing high-density lipoprotein cholesterol (HDL-C, 7.98%). XOP showed enhanced hepatoprotection (AST↓ 32.6%, p < 0.01). Although XSO elevated fecal acetate (1.5-fold) and butyrate (1.3-fold), these changes lacked significance (p > 0.05). The analysis of gut microbiota showed that the pro-inflammatory Coriobacteriaceae and Erysipelibacteriaceae were reduced at the family level in the XOP group (p < 0.05). Lipidomics identified 69 differential metabolites: XSO downregulated atherogenic cholesteryl esters and triglycerides, upregulated six phosphatidylethanolamines, and modulated aberrant lysophosphatidylcholines. Conclusions: XSO alleviates hyperlipidemia through direct modulation of lipid metabolism pathways and suppression of pro-inflammatory gut microbiota. While its prebiotic potential warrants further validation, these findings highlight XSO as a functional dietary adjunct for improving lipid homeostasis and mitigating cardiovascular risks. XSO alleviates hyperlipidemia through direct modulation of lipid metabolism pathways and suppression of pro-inflammatory gut microbiota, while its prebiotic potential warrants further validation. These findings support XSO as a dietary adjunct for lipid homeostasis improvement, offering a nutritional strategy for early-stage cardiovascular risk management.