Tirunesh Dibaba (Oromo: Xirunesh Dibaabaa, Amharic: ጥሩነሽ ዲባባ ቀነኒ; born 1 October 1985[5]) is an Ethiopian long distance runner athlete who competes in long-distance track events and international road races.

She is the one of two women (the other Sonia O'Sullivan) who won the short and long course World Cross Country title at the same championship (2005 in Saint-Galmier, France).

[8] Tirunesh comes from a sporting family of several Olympic medalists, which includes her sisters Genzebe and Ejegayehu, and her cousin, Derartu Tulu.

[12] Tirunesh's first fully international outdoor event as a junior was the 2001 World Cross Country Championships (WCCC)[10] in Ostend, Belgium where, at the age of 15, she finished fifth.

In Paris at her World Championships debut, Tirunesh won the 5000 metres in a sprint finish against Marta Dominguez of Spain and Edith Masai of Kenya.

"[14] At the Reebok Boston Indoor Games in January, Tirunesh set a world record in the 5000 meters with a finish time of 14:32.93.

"[14] Tirunesh won the long race on 1 April at the World Cross Country Championships in Fukuoka, Japan.

At the 6 June Bislett Games in Oslo, a Golden League event, Tirunesh Dibaba set a world record in the 5,000 metres which would stand for over twelve years, running the distance in 14:11.15.

[18]: 278 Six days later, Tirunesh defeated her sister Ejegayehu by 0.68 seconds in the 10,000 metres at the Golden Spike Grand Prix in Ostrava, Czech Republic.

[31] The IAAF awarded its Female Performance of the Year to Tirunesh and Czech javelin thrower Barbora Špotáková.

[32] Tirunesh was nominated for IAAF World Athlete of the Year, which was won instead by Russian pole vaulter Yelena Isinbayeva for the third time.

On 15 November, Tirunesh won the Zevenheuvelenloop 15 kilometres road race in Nijmegen, Netherlands in a world best time of 46:28.

"[35] In February, Tirunesh ran the third fastest indoor two-mile race to date[36] (9:12.23)[37] at the Aviva Grand Prix in Birmingham, U.K.

[42] On 1 June in her first outdoor track race of the year, she won the 10,000 metres at the Prefontaine Classic in Eugene, a Diamond League event, by holding off Florence Kiplagat at the finish line.

She defeated the marathon gold medalists from the 2012 Summer Olympics and the 2011 World Championships, Tiki Gelana and Edna Kiplagat, respectively, even though both ran personal bests.

[52] Tirunesh closed her year on 18 November with a win at the ABN-AMRO Zevenheuvelenloop in Nijmegen, Netherlands, setting the fastest time that season for the 15 kilometre distance.

"[54] Tirunesh had planned to run the London Marathon on 21 April, but an injury to the bottom of her heel forced postponement of her debut at this distance.

[51][55] On 1 June, Tirunesh won the 5000 metres at the Prefontaine Classic in Eugene, Oregon, U.S., a Diamond League event that doubled as Ethiopia's trials for the World Championships.

[51][56] Tirunesh on 27 June ran her last 10,000 metre race before the World Championships at the Golden Spike Ostrava in the Czech Republic.

[51] Ethiopian Almaz Ayana finished second in a personal best of 14:25.84,[51] followed by countrywomen Gelete Burka, Sule Utura, and Buze Diriba.

She shadowed the leaders during the race until taking the lead with 500 metres remaining[58] and sprinting to her fifth individual World Championships gold medal.

"[58] On 29 August, Tirunesh resumed her rivalry with Defar in the 5000 metres at the Weltklasse Zürich, a Diamond League event.

[59][60] Three days later in Tilburg, Netherlands, Tirunesh attempted to break Paula Radcliffe's 10 kilometer road race world record of 30:21.

[61] Tirunesh's final race of the season was the Great North Run in northern England on 15 September, where she was the defending champion.

Teammate Almaz Ayana smashed Wang Junxia's 22 year old (and controversial) world record (29:31.78) by 14.33 seconds on her way to the gold medal in a time of 29:17.45.

Silver medalist Vivian Cheruiyot of Kenya came within 0.75 seconds of Wang's world record while running the third fastest time (29:32.53) in history.

Mary Jepkosgei Keitany's winning finish time of 2:17:01 was a world record for a women-only marathon and was the second-fastest performance in history.

She won the silver medal in the 10,000 metres at the World Championships in London in August, finishing 46.37 seconds behind Almaz Ayana.

Tirunesh placed sixth at the Delhi Half Marathon in October and ran the San Silvestre Vallecana road 10k in Madrid on 31 December.

[76] The 37-year-old returned after giving birth to a third child running her first race since December 2018 at the Houston Half Marathon in January.