Dionicio Cerón Pizarro (born October 9, 1965 in Toluca) is a former marathon runner from Mexico, whose personal best in the classic distance was 2:08:30. He represented his native country two times at the Summer Olympics: in 1992 and 1996. He also won the London Marathon three consecutive times between 1994 and 1996, the only man to have ever achieved this feat. Eliud Kipchoge, António Pinto and Martin Lel are the only other men to have won it three times or more, however not in consecutive years. In 1990 he won the Peachtree Road Race in Atlanta, and is to date the only Mexican, male or female, to have won this prestigious 10K run.