The 1984 United States presidential election in Indiana took place on November 6, 1984. All 50 states and the District of Columbia, were part of the 1984 United States presidential election. State voters chose 12 electors to the Electoral College, which selected the president and vice president of the United States. President Ronald Reagan of California won the state of Indiana against former Vice President Walter Mondale of Minnesota by a substantial 23.99% margin. Reagan ran for a second time with incumbent Vice President and former C.I.A. Director George H. W. Bush of Texas, and Mondale ran with Representative Geraldine Ferraro of New York, the first major female candidate for the vice presidency.

Lake County is a county located in the U.S. state of Indiana. In 2020, its population was 498,700, making it Indiana's second-most populous county. The county seat is Crown Point. The county is part of Northwest Indiana and the Chicago metropolitan area, and contains a mix of urban, suburban and rural areas. It is bordered on the north by Lake Michigan and contains a portion of the Indiana Dunes. It includes Marktown, Clayton Mark's planned worker community in East Chicago.