The Men's marathon T11 was a marathon event in athletics at the 2004 Summer Paralympics in Athens, for totally blind athletes (running with a sighted guide).

Defending champion and world record holder Carlos Amaral Ferreira of Portugal took part, along with sixteen other athletes, from a total of ten countries.

No athlete had ever successfully defended his title in the men's fully blind marathon, and Ferreira failed to become the first; he took silver, finishing half a minute behind Japan's Yuichi Takahashi.

[1] The 2004 men's T11 marathon is the most recent to have been held as a distinct event.

[2] The T13 event, held at the same time as the T11, was won by Ildar Pomykalov, representing  Russia.