Kirsti Pratt (maiden name Meyer) is a personal trainer from St. Louis, Missouri, who is nicknamed "The Machine."

Kirsti first competed in American Ninja Warrior 7 at the eligible age of 21. However, she was one of many to fail the Big Dipper in Kansas City qualifying.

Kirsti returned in American Ninja Warrior 8, which by then, she had gotten married to her fiancee, Mike Pratt. Pratt was notably remembered by many for doing the Salmon Ladder in her wedding gown prior to competing. Pratt became the first competitor of the night to have conquered the Disc Runner in Indianapolis qualifying, where she failed the Swinging Spikes and missed out on advancing to the city finals, placing 32nd. Kirsti did however get a wildcard into the National finals in Vegas. On Stage 1, Kirsti was of few women to make it past the Giant Log Grip, where she fell on the Jumping Spider.

Pratt has confirmed on competing in Kansas City in American Ninja Warrior 9, just like two years ago. Her run was cut from broadcast and she didn't make the womens' top 5, Like most women she failed crank it up.