- July 2, 1990: Kayla Jean Harrison is born in Middletown, Ohio.
- Age 6: Harrison begins judo, introduced by her mother, a black belt.
- Early 2000s: Trains under coach Daniel Doyle and wins two national championships by age 15.
- 2007: Reports SA by her coach, Daniel Doyle, who is later sentenced to 10 years in prison.
Harrison and Ronda Rousey were roommates during their Judo days
- 2008: Moves to Boston to train with Jimmy Pedro and his father. Changes weight class to 78 kg and wins the Junior World Championship.
- 2010: Wins her first senior World Championship in judo in the 78 kg division, becoming the first American since 1999 to do so.
- August 2, 2012: Wins her first Olympic gold medal in judo at the London Olympics, becoming the first American to win Olympic gold in the sport.
- 2015: Inducted into the United States Judo Federation Hall of Fame.
- August 31, 2016: Wins her second Olympic gold medal in judo at the Rio Olympics. Promoted to 6th Degree Black Belt (rokudan), becoming the youngest American to hold this rank.
- October 2016: Announces her transition to MMA and signs with the World Series of Fighting.
- June 21, 2018: Makes her MMA debut at PFL 2, defeating Brittney Elkin via armbar submission.
Martin has since fallen on hard times. There were reports that Harrison may have filed for a restraining order.
In September 2021, Harrison successfully obtained a restraining order against Martin in Broward County (Fla.) after lodging allegations of domestic violence. Details of the confidential court filings are unknown. But the restraining order was extended twice before Harrison voluntarily dismissed it in March 2022.
In December 2022, Lee County (Fla.) deputies responded to a report of a “verbal disturbance” at an airbnb Martin had rented. Officers returned later that night to find Harrison crying inside a black Ford Expedition, saying she “just wanted to leave.” Moments later, Martin emerged from the home purportedly drunk and taunted and threatened the deputies. He was arrested and charged with simple assault on an officer. Martin pleaded ‘not guilty,’ and prosecutors dropped the charge seven months later.
In February 2023, Harrison filed another confidential domestic-violence complaint against Martin in Broward County. She met the same day with a sheriff’s deputy at the Statewide Prosecutors office in Fort Lauderdale. According to a Broward spokesperson, the investigation currently is “pending inactive awaiting follow-up information from the victim.”
- December 31, 2019: Wins the PFL Women’s Lightweight Championship, defeating Larissa Pacheco.
She adopted her brother’s children in 2020.
Rumors of her negotiating with the UFC first surfaced in 2021 when she attended a UFC event and rubbed shoulders with Marvin Vettori and Michael Bisping.
- November 25, 2022: Suffers her first MMA loss in a rematch against Larissa Pacheco in the PFL Women’s Lightweight tournament finals.
- March 2023: Inducted into the International Sports Hall of Fame.
- April 13, 2024: Makes her UFC debut at UFC 300, defeating former champion Holly Holm by submission.
- July 2, 2024: Ranked #3 in UFC women’s bantamweight rankings and #11 in pound-for-pound rankings.
- October 5, 2024: Scheduled to face Ketlen Vieira at UFC 307.
