Deerfield is a village in Lake County, Illinois, United States. A portion of the village is in Cook County, Illinois, United States. The population was 18,420 at the 2000 census. Deerfield is home to the headquarters of Walgreens, Baxter Healthcare, APAC Customer Services, Fortune Brands, Takeda Pharmaceuticals, and Così, and was at one time the headquarters of the Sara Lee Corporation. Deerfield High School is one of the top public schools in the state. Trinity International University, an evangelical Christian university, is located in Deerfield. Deerfield is represented by the 10th Congressional District of Illinois, 29th District of the Illinois Senate, and the 58th District of the Illinois House of Representatives.