At the 2012 United States Olympic Trials, the qualifying meet for the 2012 Olympics, Smoliga missed the Olympic team by finishing fourth in the 100-meter backstroke (1:00.46) and twenty-third in the 50-meter freestyle (25.66).[6][7] During the semifinals, Smoliga swam a personal best of 59.82 breaking the long course one-minute barrier for the first time.[8]
At the Illinois State High School Championships in November 2012, Smoliga broke the national high school records in both the 100-yard backstroke (51.43) and 50-yard freestyle (21.99).[4]
At the 2012 FINA Short Course World Championships in Istanbul, her first major international competition, Smoliga won a total of four medals: two gold, one silver, and one bronze. In the 100-meter backstroke final, Smoliga surprised the field by winning gold in a time of 56.64 swimming from lane 1. In the last 50-meters, Smoliga had the fastest split in the field with a time of 29.74.[9] Smoliga also earned gold in the 4×100-meter freestyle relay, silver in the 50-meter backstroke (in which she set the American record), and bronze in the 4×100-meter medley relay.
She was struck with mononucleosis prior to the 2014 Phillips 66 National Championships, leading her to bad results in both that championship and the 2015 NCAA tournament. However, being the fifth best time at the 100m backstroke, she retained her spot at the national swimming team, and was qualified for the 2015 Pan American Games.[11] She won the silver at the 100m backstroke with a 1:00.06, her third fastest time ever.[12]
At the 2018 World Championships in Hangzhou, China, Smoliga won a record eight gold medals, setting a new Guinness World Record for the "most number of gold medals won at a single FINA World Championships" (short course or long course) by one swimmer, and breaking the former record of seven gold medals held by Michael Phelps and Caeleb Dressel.[2][3] Smoliga went eight-for-eight at the Championships, winning the gold medal in every event she raced.[15]
2020 Tokyo Olympics
On the 2nd day of the 2020 U.S. Olympic Trials, Olivia Smoliga swam the prelim heats of the 100 backstroke touching 4th with a time of 59.24, just enough to secure a lane for the semifinals.[16] During the semifinals, Smoliga won her heat with a 58.50, making her 2nd seed for the final.[17]
On the 3rd day of the Trials, Olivia Smoliga scratched out of the 200 freestyle to focus on the 100 Backstroke final. During the final, Smoliga turned up just short of her 2nd Olympic berth, falling 12 hundredths behind Rhyan White.[17]
On the sixth day of trials, Olivia posted a time of 53.63 in the 100 freestyle final to earn a spot on the Olympic team as a member of the 4x100 freestyle relay team.[18][19]
At the Olympic Games, Olivia swam the lead-off leg during the prelims of the 4x100 Freestyle Relay, Splitting a 54.06. She was not chosen to swim in the finals.
International Swimming League
In 2019 Olivia was a member of the inaugural International Swimming League representing the Cali Condors, who finished third place in the final match in Las Vegas, Nevada in December. She was a top 10 point scorer for the season winning many events including the 50 back in the final.[20]