The Chicago Marathon's race course is renowned for its flat and fast characteristics, making it a favored event for runners aiming to achieve personal bests or qualify for other marathons. The starting line is located in Grant Park, near the city's iconic skyscrapers, offering a picturesque and energetic environment. As participants set off, they encounter a relatively flat route that takes them through the city's downtown area. The first half of the course highlights Chicago's architectural marvels such as the Willis Tower, Tribune Tower, and the Chicago Theater. As runners continue, they cross over the Chicago River and pass through several vibrant neighborhoods, including Old Town and Lincoln Park.

In the second half of the race, participants journey through the historic and culturally diverse areas of Boystown, Little Italy, and Pilsen. One of the unique features of the course is the cheering crowd that lines the streets, providing unparalleled support and motivation throughout the event. As the marathon progresses, runners make their way back to the city center, along the lakefront path, passing by the iconic Buckingham Fountain, and enjoying scenic views of Lake Michigan.

Approaching the final miles, participants encounter a challenging section, known as "Mount Roosevelt" by some runners. Although only a minor incline, it can be mentally challenging after miles of predominantly flat terrain. However, this hill is short-lived, and soon runners find themselves descending towards the iconic finish line on Columbus Drive. Overjoyed by the enthusiastic crowd and the sense of accomplishment, participants endure the final sprint to reach the coveted finish arch in Grant Park, culminating their remarkable journey through the heart of Chicago.

Overall, the Chicago Marathon's course is largely flat, with minor inclines and declines throughout. The urban landscape, diverse neighborhoods, and unwavering crowd support make this course a favorite among runners looking for a memorable and inspiring marathon experience.