John Joseph "Johnny" Hayes (April 10, 1886 – August 25, 1965) was an American athlete, a member of the Irish American Athletic Club, and winner of the marathon race at the 1908 Summer Olympics. Hayes' Olympic victory contributed to the early growth of long-distance running and marathoning in the United States. He was also the first man to win a marathon at the now official standard distance of 26 miles 385 yards when Olympic officials lengthened the distance to put the finish line in front of the Royal Box (the 1896 and 1904 Olympic marathons had been less than 25 miles long).