Henry Harold "Harry" Green (15 July 1886 – 12 March 1934) was a British long-distance runner who competed in the marathon at the 1912 Summer Olympics and is recognized by the International Association of Athletics Federations as having set a world's best in the marathon on 12 May 1913 with a time of 2:38:16.2 in London. Green was a member of the Herne Hill Harriers.
Green competed for the Sutton Harriers and won a marathon in Surrey on Boxing Day 1908. At the inaugural Polytechnic Marathon run in London on 8 May 1909 he finished third, behind Henry Barrett and Fred Lord, with a time of 2:49:00.8. Although the 1910 Polytechnic Marathon was cancelled due to the death of King Edward, Green was one of 49 who started the 1911 race that made its way from Windsor Castle to Stamford Bridge. Competing for the Surrey Athletic Club, Green trailed Michael Ryan until Putney, 23 miles into the race. Taking the lead, he finished four minutes in front of Ryan with a time of 2:46:29.8. The New York Times described him as being in "fresh condition" at the end of the race.
Green was the favourite to win the 1912 Polytechnic Marathon, a race that also served as "England's tryouts for the Olympic games", but finished third behind James Corkery of Canada and Christian Gitsham of South Africa. During the 1912 Summer Olympics, he finished fourteenth in the marathon. In May 1913 Green broke the world marathon record at a track in Shepherds Bush, with a time of 2h, 38m, 16.2s. Green's record lasted nineteen days. On 31 May 1913, Alexis Ahlgren of Sweden eclipsed Green's mark with a 2:36:06 performance at the Polytechnic Marathon.
Green worked at Harrods until he signed up as a private during World War I. He was decorated with the Distinguished Conduct Medal and the French Médaille militaire for his service in the Gallipoli Campaign. Commissioned on the battlefield, he left the army with the rank of Captain. After the war he ran a newsagents shop in Knights Hill, West Norwood and did not actively participate in major competitions. Green died of pneumonia in 1934. He was cremated at West Norwood Cemetery.
- Butler, Mark, ed. (2011). 13th IAAF World Championships In Athletics: IAAF Statistics Handbook. Daegu 2011 (PDF). Monaco: IAAF Media & Public Relations Department. pp. 595, 612, 614–615. Archived from the original (pdf) on October 1, 2012. Retrieved September 29, 2011.
- "ENGLAND'S OLYMPIC TRYOUTS; C.N. Seedhouse Equals Hillman's 400-Metre Record -- Corkery's Marathon" (PDF). The New York Times. 19 May 1912. Retrieved 2 October 2011.[permanent dead link]
- "Virgin London Marathon - In Harry's name". London Marathon. 7 April 2011. Archived from the original on 2011-04-10. Retrieved 5 October 2011.
- "The Polytechnic Hariers: Marathon Race And Sports". The Times. May 10, 1909. Retrieved September 30, 2011.
- Lambie, James. "A Marathon Trophy". The Story of Your Life: A History of the Sporting Life Newspaper (1859-1998. Leicester, UK: Troubadour Publishing Ltd. pp. 276–278. ISBN 9781848762916. Retrieved September 29, 2011.
- "Polytechnic Harriers Marathon". Association of Road Racing Statisticians. September 16, 2011. Retrieved 30 September 2011.
- "MIKE RYAN SECOND IN RACE.; Irish-American Runner Weakens In Marathon in England" (PDF). The New York Times. 28 May 1911. Archived from the original (PDF) on 2011-10-15. Retrieved September 30, 2011.
| Men's Marathon World Record Holder
May 12, 1913 – May 31, 1913