Twin Groves Wind Farm is a wind farm in the U.S. state of Illinois near the villages Arrowsmith, Saybrook, and Ellsworth in McLean County. It consists of 240 operating wind turbines. Each wind turbine stands 270 ft (65.23 m) tall and has three 85 ft (35.91 m) long blades. The wind farm was constructed from 2007 to February 2008. Twin Groves was the largest utility scale wind farm east of the Mississippi River upon completion.
The Twin Groves Wind Power Plant lies in eastern McLean County just east of Bloomington on Illinois State Route 9. The wind farm consists of 240 Vestas 1.65 MW wind turbines and is owned and operated by Horizon Wind Energy. Total cost of Twin Groves was approximately $700 million. The towers are spread out over 22,000 acres (89 km2) of McLean County, near the villages of Arrowsmith, Ellsworth, and Saybrook. The current total capacity at Twin Groves Wind Farm is 398 megawatts. The site produces enough power to power about 120,000 homes, or approximately 1.3 billion kilowatt hours annually.

As well as generating power, the wind turbines provide an added benefit to the local economy. Only 150-200 acres or (1%) of the total 22,000 acres (89 km2) will be taken up by the turbines. This will supplement local farmers who lost such land. Royalties are paid to owners of the land at $5,000 per wind turbine. The two adjacent school districts also benefit from the property taxes brought in, Ridgeview School District will start collecting $300,000 a year, while Tri-Valley School District will collect between $200,000-$250,000 a year.

With 240 wind turbines already generating power, Horizon Wind Energy is considering to add an additional 170 wind turbines, to bring the total number of turbines to 410. Test wind turbines are being placed in eastern McLean County to determine if additional wind turbines can be supported. If constructed, power generation estimates for the wind farm increase from 398 megawatts to 680 megawatts.