Sifan Hassan (Oromo: Siifan Hassan; born January 1993 in Ethiopia) is an Ethiopian-Dutch middle- and long-distance runner. She is most recognized for her versatility in running championship and world-leading performances in widely disparate distances. She completed an unprecedented triple at the 2020 Tokyo Olympics, winning gold medals in both the 5,000 metres and 10,000 metres and a bronze medal for the 1,500 metres. Hassan is the only athlete in Olympic history to win medals across a middle-distance event and both long-distance races in a single Games. She is only the second of three women to complete an Olympic distance double. At the Paris 2024 Olympics, Hassan secured a bronze medal in both the women's 5,000 m and 10,000 m events and gold in the women's marathon, becoming the only woman to win the Olympic gold medal in the 5,000 metres, 10,000 metres and Marathon races.

At the World Athletics Championships, Hassan took 1,500 m and 10,000 m titles in 2019, becoming the only athlete (male or female) in history to win both events at a single World Championships or Olympic Games. She won a bronze at the 1500 m in 2015, and at the 5000 m in 2017, when she also finished fifth in the 1,500 m. Hassan is a three-time World Indoor Championships medallist, winning gold at 1500 m in 2016 as well as silver at 3000 m and bronze for 1500 m in 2018. She earned six European medals (including two cross country titles), and one European indoor medal. She is also a three-time Diamond League winner, having secured the 1500 m/5000 m double in 2019. In her debut over the classic 26.2-mile distance, she won the 2023 London Marathon.

Hassan has been the world record holder for the one hour run since 2020. She held the world record for the one mile on the track from July 2019 to July 2023, when Faith Kipyegon overtook it. She held a world record at 10,000 m for two days in June 2021. She holds six European records (1500 m, 3000 m, 5000 m, 10,000 m, half marathon, marathon) and three other Dutch records.

Hassan was born in Adama, Oromia, Ethiopia and raised in the countryside of Kersa in the Munesa district of the Arsi Zone of Oromia. She was a recreational runner there. She left her home country as a refugee and arrived in the Netherlands in 2008 at age 15. She began running while undertaking studies to become a nurse. She is an Arsi Oromo.

Hassan became a Dutch citizen in 2013. Born Orthodox Christian, she later converted to Sunni Islam.

She got her first spikes and kit from Yke Schouwstra. After she moved to Eindhoven, she met Ton van Hoesel who coached her for two years. In Arnhem, Hassan became a member of the Papendal national training centre for top athletes. She received her Dutch citizenship in 2013. Affiliated with Eindhoven Atletiek, Hassan entered the Eindhoven half marathon in 2011 and won the race with a time of 77:10 minutes. She was also runner-up at two cross country races (Sylvestercross and Mol Lotto Cross Cup). She won those races in 2012, as well as the 3000 m at the Leiden Gouden Spike meet.

Hassan made her breakthrough in the 2013 season. She ran an 800 metres best of 2:00.86 minutes to win at the KBC Night of Athletics and took wins in the 1500 m at the Nijmegen Global Athletics and Golden Spike Ostrava meets. On the 2013 IAAF Diamond League circuit she was runner-up in the 1500 m at Athletissima with a personal best of 4:03.73 minutes and was third at the DN Galan 3000 m with a best of 8:32.53 minutes—this time ranked her the fourth-fastest runner in the world that year.

Hassan became a Dutch citizen in November 2013, too late for competing at the 2013 World Championships, and the following month she made her first appearance for the Netherlands. At the 2013 European Cross Country Championships she won the gold medal in the under-23 category on a 6 km course in a time of 19:40 ahead of Amela Terzic and helped the Dutch team to third in the rankings. She also won the Warandeloop and Lotto Cross Cup Brussels races that winter.