The New York City Marathon, currently branded as the TCS New York City Marathon for sponsorship reasons, is an annual marathon (42.195 km or 26.219 mi) that courses through the five boroughs of New York City. It is the largest marathon in the world, with 53,627 finishers in 2019 and 98,247 applicants for the 2017 race. Along with the Boston Marathon and Chicago Marathon, it is among the pre-eminent long-distance annual running events in the United States and is one of the World Marathon Majors.

The race is organized by New York Road Runners and has been run every year since 1970, with the exception of 2012, when it was cancelled due to the landfall of Hurricane Sandy, and 2020, when it was cancelled due to the COVID-19 pandemic. The race is held on the first Sunday of November and attracts professional competitors and amateurs from all over the world. Because of the popularity of the race, participation is chosen largely by a lottery system. Guaranteed entry to the marathon can be gained by satisfying the requirements of the 9+1 program or the 9+$1K program (where NYRR members run in nine sponsored races and either volunteer at another event or donate $1,000 to support NYRR programs for young athletes), having completed 15 or more previous NYC Marathons, or meeting time qualification standards. In addition, runners can gain an entry by joining a team to raise funds for one of a number of charities.