The 2013 Boston Marathon is the 117th version of the historical event, which was first held in 1897. The Boston Marathon is the world's oldest annual marathon and one of six World Marathon Majors.

The race, which runs through 26 miles 385 yards (42.195km), is always held on the Patriot' Day, the third Monday of April. It attracts about 20,000 athletes around the world each year, one of the world largest marathon.

Through 2005, the race began at noon. As of 2013, the starting time for the elite women was 9:32 a.m., and was 10:00 a.m. for the elite men and wave one. The wave three started on 10:40 a.m..

The Boston Marathon is the most widely-viewed sporting event in New England with about 500,000 spectators.

Two explosions occurred at the 2013 Boston Marathon, causing at least two deaths and about 100 injuries, according to reports.