Meili swam for Columbia University until she graduated in 2013. In 2012 at the NCAA Championships, Meili finished fifth in the 100Y breaststroke. During her senior year, 2013, Meili finished third in the 100Y Breaststroke and 7th in the 200Y Individual Medley.
In 2014 at the US Short Course Nationals, won gold in the 200Y IM and 100Y Free, silver in the 100Y Breaststroke, and bronze in the 200Y Breaststroke. At the Long Course US Nationals, Meili finished 3rd in the 50 Breaststroke, 5th in the 100 Breaststroke, 9th in the 50 Free and 14th in the 100 Free.
At the 2015 US Long Course Nationals, Meili won the 100Breaststroke and 13th in the 50 Free.
Meili represented the US for the first time at the 2015 Pan American Games, winning gold in the 100M Breaststroke, as part of the 4 x 100 Medley Relay and silver on the 4 x 100 Free Relay.
2016 US Olympic Trials
Meili finished second in the 100M Breaststroke behind Lilly King with a time of 1:06.07. With that 2nd place finish, Meili assured herself a spot on the US Team heading to Rio.
2016 Rio Olympics
Katie Meili made it a 1-3 finish for the American women in the 100M Breaststroke. She won the bronze behind American Lilly King and Russian swimmer, Yulia Efimova. Just 19 one hundredths out of the silver medal.