Digestive properties of starch can be significantly modified by its interaction with polyphenols. This study focused on the modulatory effect of tea polyphenol-fortified parboiled rice (TP) on high-fat diet (HFD)-induced obesity in mice through the regulation of gut microbiota. TP was prepared with parboiled rice (PR) by soaking with tea polyphenols (TPs). The results showed that average body weight of mice fed with an HFD containing PR (PR-H) or TP (TP-H) decreased by 24.5% and 48.7%, compared with the group of an HFD containing white rice (WR-H), respectively. The levels of total triglyceride and total cholesterol were ranked as WR-H > PR-H > TP-H. Histological sections of the liver and epididymal adipose tissue showed that TP reduced lipid accumulation in mice fed with an HFD. Additionally, TP enhanced the liver antioxidant capacity and reduced oxidative damage in mice, thereby ameliorating liver oxidative stress caused by the HFD. Besides, TP modified the microbial community of mice by improving the gut microbiota diversity with the abundance of Akkermansiaceae, Muribaculaceae, and Bacteroidaceae increased. These findings suggested that TP can improve the intestinal microecological environment of mice, regulate lipid metabolism levels, and thereby exert a certain anti-obesity effect.