The 2010 Chicago Marathon was the 33rd edition of the annual marathon race held in Chicago, Illinois. It took place on Sunday, October 10, 2010. The event was one of the five races comprising the World Marathon Majors at the time, alongside the marathons in Berlin, Boston, London, and New York City.
The race is noted for its competitive elite field and unseasonably warm weather conditions. Temperatures reached approximately 83°F (28°C), which prompted organizers to activate a "yellow flag" caution level and eventually a "red flag" level to warn participants of the heat. Despite the conditions, 38,132 participants finished the race, which was a record for the event at that time.
In the men's elite race, Kenya's Samuel Wanjiru won the event with a time of 2:06:24. The finish was characterized by a tactical battle between Wanjiru and Ethiopia's Tsegaye Kebede. The two runners traded the lead several times in the final miles before Wanjiru secured the victory by a margin of 19 seconds. This performance was significant as it was Wanjiru's final major marathon victory before his death in 2011.
In the women's elite race, Liliya Shobukhova of Russia was the first to cross the finish line with a time of 2:20:25, followed by Astede Baysa of Ethiopia. However, in 2014, Shobukhova’s results from 2009 to 2011 were annulled by the Russian Athletics Federation and the International Association of Athletics Federations (IAAF) due to abnormalities in her biological passport linked to doping. As a result, Shobukhova was stripped of her title, and Astede Baysa was later recognized as the official winner of the 2010 women's race.
The wheelchair division was won by Heinz Frei of Switzerland in the men's category (1:26:56) and Tatyana McFadden of the United States in the women's category (1:47:17).
