1904 – An event in the Olympic Games was called triathlon consisting of the long jump, shot put and 100-yard dash 

September 1974 – While advertising its new race, the San Diego Track Club newsletter headline read, “Run, Cycle, Swim – Triathlon set for 25th,” using the word “triathlon” for the first time in the modern sense. 

Sept. 4, 1994 – At the 103rd IOC Session in Paris, triathlon was officially included on the Olympic Program starting with the Sydney Olympic Games of 2000. Triathlon was placed on the program on a provisional basis, meaning the sport would be re-evaluated after the Sydney Olympic Games to determine if it would remain on the program. 

May 27-28, 2000 – The first U.S. Olympic Triathlon Team Trials took place in Dallas, Texas, selecting the team that competed at the Sydney Olympics. 

Sept. 16-17, 2000 – Triathlon makes its long awaited Olympic Games debut as the women’s triathlon opens day one of competition at the 2000 Sydney Olympic Games. Switzerland’s Brigitte McMahon shocks the field and is crowned the first gold medallist. Joanna Zeiger of the U.S. places fourth, while Sheila Taormina finishes sixth in the women’s event. In the first men’s triathlon of the Olympic Games, Canadian Simon Whitfield came from behind with the fastest run split to claim gold. 

Aug. 25-26, 2004 – Triathlon makes its second appearance at the Olympic Games in Athens. Austria’s Kate Allen comes from behind on the run and pulls off a stunning upset to claim Olympic gold. The United States’ Susan Williams wins the bronze for the first Olympic medal for an American. Hamish Carter of New Zealand won the men’s gold medal. 

Aug. 18-19, 2008 – Triathlon makes its third appearance at the Olympic Games in Beijing.  Australia’s Emma Snowsill and Germany’s Jan Frodeno are victorious, becoming new Olympic gold medallists. Laura Bennett of the U.S. places fourth, narrowly missing the podium.
Aug. 4 & 7, 2012 – The women's triathlon event makes a splash with a remarkable sprint to the gold, ending in a photo finish. Switzerland's Nicola Spirig finished just ahead of Lisa Norden to become the women's Olympic champion. American Sarah Groff (now Sarah True) finished fourth. In the men's race, Alistair Brownlee won gold in his home country. 

Aug. 18 & 20, 2016 - The U.S. makes history with Gwen Jorgensen winning gold at the Rio Olympic Games. Alistair and Jonathan Brownlee repeat as Olympic medalists, with Alistair winning another gold. 

Sept. 11, 2016 - Triathlon makes its debut at the 2016 Rio Paralympic Games. Allysa Seely, Hailey Danisewicz, and Melissa Stockwell swept the PT2 category. Additionally, Grace Norman won gold in the PT4 category.

July 26-27 & 31, 2021 - Katie Zaferes wins bronze behind Bermuda’s Flora Duffy and Great Britain’s Georgia Taylor-Brown for the United States’ third individual women’s Olympic Games medal. Norway’s Kristian Blummenfelt wins gold in the men’s individual race with cancer survivor Kevin McDowell posting the highest-ever U.S. men’s finish in sixth. In the debut of the Mixed Relay, the American team of Katie Zaferes, Kevin McDowell, Taylor Knibb and Morgan Pearson won silver behind Great Britain.  

Aug. 28, 2021 - Brad Snyder takes home the first men's PTVI gold medal with his guide, Greg Billington. Kendall Gretsch also secured a gold medal in the women's PTWC category, while Allysa Seely and Hailey Danz earned a gold and silver, respectively, in the PTS2 category. Grace Norman secured a silver in the women's PTS5 category.

• The Tokyo Games were delayed one year due to the COVID-19 pandemic. 

July 31 & Aug. 5, 2024 - The U.S. Mixed Relay team of Seth Rider, Taylor Spivey, Morgan Pearson and Taylor Knibb won silver in dramatic fashion at the Paris 2024 Olympic Games. In an epic sprint on the historic Pont Alexandre III bridge, Knibb out-leaned Great Britain's Beth Potter with just 0.005 of a second separating silver and bronze. Germany took the gold. In the individual races, France's Cassandre Beaugrand won gold in front of her home crowd while Great Britain's Alex Yee took gold for the men. The men's race was delayed one day due to water quality. 

Sept. 2, 2024 - Paratriahletes brought home a total of eight paratriathlon medals across multiple classifications, the most in Paralympic Triathlon history. Grace Norman and Chris Hammer swept the PTS5 category, Hailey Danz, Mohamed Lahna, Mark Barr, and Allysa Seely secured four medals in PTS2 (including one gold, one silver, and two bronze), Carson Clough earned a silver medal in PTS3, and Kendall Gretsch added a silver medal in the PTWC competition.