At 25 years old, Katelyn Ohashi has this physical status:
Early in her career, Ohashi trained with Al Fong at Great American Gymnastics Express (GAGE) in Blue Springs, Missouri. Ohashi was twelve years old when she made her debut on the national gymnastics scene at the 2009 Junior Olympic National Championships, where she placed first on floor exercise, tied for second on uneven bars, placed fourth in the all-around and tied for seventh on vault.
She competed in her first elite meet at the 2009 U.S. Classic in Des Moines, Iowa, where she placed fourth on floor in the junior division, tied for fifth on balance beam and placed ninth in the all-around. This qualified her for the National Championships in Dallas, where she won the silver medal on floor, placed sixth on beam, finished tenth in the all-around and was named to the junior national team.
Soon after Nationals, Ohashi moved to Plano, Texas, to train at WOGA.
In the junior division of the 2010 U.S. Classic in Chicago, Ohashi won silver medals in the all-around and on bars, beam and floor. At the National Championships in Hartford, Connecticut, in July, she won the bars title, placed third in the all-around and tied for fourth on floor. She placed fifth on beam and seventh on vault.
At the 2010 Bumbo Cup in Pretoria, South Africa, Ohashi captured the junior-division gold medals in the all-around, floor and vault, along with silver medals on bars and beam.
In the junior division at the 2011 City of Jesolo Trophy, Ohashi helped the U.S. win the team competition and won an individual gold medal on floor. She tied for second on uneven bars and placed third all-around, fourth on beam and fifth on vault.
At the U.S. Classic in Chicago, she won the silver medal on beam with a score of 14.95, and tied for fifth on vault with Kiana Winston (14.55). At the National Championships in August, she won the junior all-around title with a total score of 120.95 over two nights, beating defending champion Kyla Ross.
Ohashi captured the bars title at Nationals with skills that included an el-grip endo to straddled Jaeger, a Gienger and a tucked double-double dismount. Her winning beam routine, one of the most difficult in the world, featured a full-twisting back layout, a standing Arabian, an Onodi and a piked full-in dismount. She also won floor with a routine that included a piked full-in and a two-and-a-half twist to front full. On vault, she performed a double-twisting Yurchenko and finished fourth.
Ohashi won the 2013 American Cup in March, defeating U.S. teammate Simone Biles. In April, however, she had shoulder surgery, which prevented her from competing for the rest of the year.
In an interview at the 2014 WOGA Classic, Ohashi said she was unsure of her ability to continue at the international elite level after her injury. Later in the year, she suffered from two torn shoulders and a spine injury that required surgery, and did not compete again until 2015.
In 2015, Ohashi dropped from elite competition back to Level 10. Her first competition since 2013 was the Texas Prime Meet, where she performed only on vault, beam and floor.
Ohashi competed at the 2015 Pikes Peak Cup in Colorado Springs on February 6. She placed 17th in the all-around competing on three events instead of four, and finished second in the vault event final with a score of 9.850. She then competed at the 2015 WOGA Classic on February 14 and placed 14th overall, competing in only three events. On February 20, she competed at the Legends Invitational in Los Angeles, where she placed 13th in the all-around and second on vault.
Ohashi joined the UCLA Bruins gymnastics team for the 2015–2016 season and was the Pac-12 Freshman of the Week four times. However, in a meet against the Arizona Wildcats, the cap of Ohashi's balance beam fell off, causing her to land on her neck upon dismount. Tests showed that she had sustained a sternal fracture, an injury that kept her out for four weeks. The following season, Ohashi finished the regular season at No. 1 on balance beam and received two perfect 10s. In the 2018 season she improved upon her performances from the previous season. She captured three perfect 10s on floor, the first of her career, and set career highs on the uneven bars, vault and the all-around. She finished the regular season ranked first on floor and third on beam, and was named the PAC-12 specialist of the year. Going into the national championships she competed on beam and floor, placing fourth on beam and winning the floor title, her first national championship win. She followed this up with another national championship win the next night with the UCLA team in the Super Six, where Ohashi scored a pair of 9.95s on beam and floor. At the 2019 Collegiate Challenge, she earned perfect 10s for a floor routine to an R&B and pop hits medley that she was performing for the second time and that has been shared widely on social media.
In 2021, Katelyn Ohashi participated in Simone Biles' "Gold Over America Tour".