1. Chicago Marathon

Now in its 42nd year, this prestigious race draws more than 40,000 runners from more than 100 countries and all 50 states. The race, which starts and ends in Grant Park, wends through 29 Chicago neighborhoods. Some 1.7 million spectators gather to cheer on the athletes. Next: October 2020
Photo: Joseph Oliver
2. Arlington Million

Around 20,000 international jockeys, horse owners, trainers, and fans make it out to this annual thoroughbred race, which offers a million-dollar purse. In 2019, the big winner was a horse named Bricks and Mortar, whose jockey was Irad Ortiz, Jr. Next: August 2020
Photo: Cal Sport Media via AP Images
3. Shamrock Shuffle

Considered the kickoff for Chicago’s outdoor running season, the road race blends an 8K run with a two-mile walk. Some 20,000 local runners participate in the downtown event, and many don green costumes inspired by the Shamrock theme. Next: March 22, 2020
Photo: Courtesy of Bank of America Shamrock Shuffle
4. Bike the Drive

Held over Memorial Day weekend, this event allows some 20,000 cyclists to pedal down a car-free stretch of Lake Shore Drive for five hours. Some cyclists opt to bike the entire 30-mile course, which goes from 57th Street to Hollywood. The ride raises money for the Active Transportation Alliance. Next: May 2020
Photo: Anne Evans
5. Chicago Polar Plunge

The 2019 plunge broke all fund-raising records in the event’s 19-year history: It raked in $1.8 million (the 2018 event raised $1.6 million.) More than 4,200 registered plungers and 600 teams participated in the event by plunging into the frigid waters of Lake Michigan. Big-name plungers included actor David Eigenberg and a team comprised of Chicago aldermen. Next: March 1, 2020
Photo: Courtesy of Chicago Polar Plunge
6. Susan G. Komen's Mother's Day Race for the Cure

Nearly 4,000 participants showed up at this holiday run, which raised more than $525,000 to help fund research and support underserved communities. Highlights of the event—meant to inspire feelings of health and happiness—included the “Shades of Pink Powder Path.” Along the path, volunteers doused runners in pink powder. Next: May 10, 2020
Photo: Michael Rataj
7. Chicago Triathlon

A Chicago tradition for 37 years, this event usually tests competitors in swimming, biking, and running. But rough waters during the event forced planners to think fast, and ultimately the swimming leg of the race was replaced with a .75 mile run. Billed as one of the largest triathlons in the world, it lured approximately 8,900 athletes in 2019. Participants came from 48 states and 22 countries. Next: August 29-30, 2020
Photo: Ali Engin
8. AIDS Run & Walk Chicago

More than 2,500 participants gather for this city race. Along with a 5K walk and a 10K run, the evening features a beer garden and opening and closing ceremonies. This year’s run raised money for the AIDS Foundation of Chicago, along with 27 other charitable groups. Next: Fall 2020
Photo: Ashley Brown and Brian Solem/AFC
9. PAWS 5K Walk/Run

This dog-friendly race, which raises money to support homeless animals, drew around 4,000 participants. After the race, attractions included a dog agility course, a “doggy oasis” with pools and smoothies, and activities for kids. Participants who raised $250 or more were entitled to visit the Hero Hangout, which offered cocktails and a playpen of adoptable dogs. Next: June 2020
Photo: Brian Hlavacek
10. Race to Mackinac

This 333-mile yacht race starts in Lake Michigan and ends in Lake Huron. About 3,000 sailors from 15 states and an array of countries, including Canada and China, participated in this year’s race. Organized by the Chicago Yacht Club, the 111-year-old event is billed as the world’s oldest annual freshwater distance race. Next: July 18, 2020
Photo: Courtesy of Chicago Yacht Club