Peoria County is divided among three different legislative districts - the 73rd, the 91st, and the 92nd District. The 73rd Legislative District includes most of the City of Peoria north of Glen Avenue and the northern and western townships in Peoria County, which includes Akron, Brimfield, Chillicothe, Elmwood, Hallock, Jubilee, Logan, Medina, Millbrook, Princeville, Radnor, Rosefield, and Trivoli Townships.

The Village of Bartonville (and Limestone Township), by itself, is divided among the 73rd, 91st, and 92nd Legislative Districts as well. The portion within the 73rd District is mostly the area west of Airport Road.

Woodford County is not entirely within one single legislative district either. For the most part, if you live north of Illinois State Route 24 and west of Interstate 39, then you probably live within the 73rd Legislative District.

The 73rd district includes Cazenovia, Clayton, Greene, Linn, Metamora, Roanoke, Partridge, Spring Bay, and Worth Townships. This encompasses the cities of Bayview Gardens, Benson, Germantown Hills, Lowpoint, Metamora, Roanoke, Spring Bay, and Washburn.

A small portion of Eureka also lies within the 73rd District, specifically the northern (north of State Route 24) and western (west of Main Street) areas of the city.

All 12 townships in Marshall County are within the 73rd Legislative District. The townships in Marshall County are: Bell Plain, Bennington, Evans, Henry, Hopewell, Lacon, La Prairie, Richland, Roberts, Saratoga, Steuben, and Whitefield. This includes the following towns: Hopewell, La Rose, Lacon, Sparland, Toluca, Varna, and Wenona.

A relatively small portion of Bureau County lies within the 73rd Legislative District. It includes Arispie, Indiantown, Milo, and Wheatland Townships and about half of Wyanet Township.