The Paris Marathon (French: Marathon de Paris) is an annual marathon hosted by the city of Paris, France. It is the largest running event in France in terms of finishers and is typically among the five largest marathons in the world.

The marathon begins along the Champs-Élysées, runs southeast through the city to the Bois de Vincennes, heads back through the city along the River Seine, and finishes on Avenue Foch.

The first Paris Marathon, the Tour de Paris Marathon, took place in 1896. A big crowd gathered to watch 191 participants. It was run over a course of 40 km (25 mi) from Paris to Conflans-Sainte-Honorine via Versailles, and the organisers decided to award a commemorative medal to all runners who finished the race in less than 4 hours.

The distance of 40 km was chosen as it was the distance separating Marathon from Athens. The current distance of the race is 42.195 km, which the IAAF established in 1921 as the standard length of a marathon, following the 1908 Olympic race in London.

This first race was won by Len Hurst from England who crossed the finishing line in 2 hours, 31 minutes and 30 seconds. His prize money was 200 francs.

Some sources, including the Association of Road Racing Statisticians, consider Frenchwoman Marie-Louise Ledru as the first female to race the now-defined marathon distance of 42.195 km, as she set a time of 5 hours and 40 minutes during the 1918 edition of the Tour de Paris, while other sources, including the International Association of Athletics Federations, credits Violet Piercy as the first to do so.

The present Paris Marathon dates from 1976. It is normally held on a Sunday in April and is limited to 50,000 runners. It is organised by the Amaury Sport Organisation. It is notable for the attractive route through the heart of the city of Paris.

Unlike most other marathons, but like all races in France, the Paris Marathon requires a doctor's note no more than a year old, stating that there is "no contraindication to competitive running".