- On 29 July 2021, she qualified 6th in the 800m freestyle and finished 4th at the 2020 Tokyo Olympic Games at the age of 15.
- She won the 2021 USA Swimming 5 km Junior National Championships in 1:04:04 at the age of 15.
- She finished 2nd in the 2019 USA Swimming Junior National Open Water Swimming Championship 5 km race in 1:02:26 at the age of 13.
- She finished 4th in the 2021 USA Swimming National Open Water Swimming Championships 10 km in Fort Myers, Florida on 16 April 2021 in 2:05:25 at the age of 15.
- She won the 5 km race at the 2021 USA Swimming Junior National Open Water Swimming Championships in Fort Myers, Florida on 17 April 2021 at the age of 15.
- Katie Grimes Nearly Joins Her Open Water Colleagues On The Olympic Podium
- Ilya Kharun and Luke Ellis Go 1-2 as the Sandpipers of Nevada Swim Very Fast
- Kathryn Grimes Wins Junior Nationals On Day 2 In Fort Myers
- Erica Sullivan Upsets Ashley Twichell and Haley Anderson to Win National Championship
- Chase Travis Wins USA Junior Nationals 5K
- World Open Water Swimming Association
- Open Water Swimming
- Marathon Swimming
- Olympic 10K Marathon Swim
- World Marathon Swimming Association
- The Rivalry Continues: Haley Anderson vs. Ashley Twichell
- Team USA
- Meet Katie Grimes, the 15-year-old USA swimmer dubbed 'the future' by Katie Ledecky
- Katie Grimes is more than the ‘future’ of swimming with impressive Olympic showing