Greece hosted the first modern Olympic marathon in 1896.
The race was held at the inaugural modern Olympic Games in Athens. It linked the town of Marathon with the Panathenaic Stadium, reflecting the ancient Greek story of a messenger associated with the Battle of Marathon. Spyridon Louis won the race for Greece, but this question concerns the host country rather than the winner.
The marathon was not part of the ancient Olympic Games. It was created for the 1896 programme by organisers who wanted an event connected with classical Greek history. The race quickly became one of the Olympics’ signature endurance events.
The original 1896 course was shorter than the modern standard distance. Marathon length was later influenced by the 1908 London Olympic route and eventually standardised at 42.195 kilometres. Greece therefore occupies a special place in both the historical inspiration and the modern sporting development of marathon running.