Ali was selected to represent the U.S. in Shenzhen, China for the World University Games where she won the Gold Medal in a time of 12.85.
At the 2013 USA Outdoor Track and Field Championships Ali took third in the 100 m hurdles to qualify for the 2013 World Championships in Athletics. At the World Championships, Ali was a semi-finalist in the 100 m hurdles, ultimately finishing 10th.
At the 2014 USA Outdoor Track and Field Championships Ali took eighth in the 100 m hurdles.
She won the 60 meters hurdles at the 2013 USA Indoor Track and Field Championships in Albuquerque, New Mexico in a personal best of 7.93 and repeated the year later with a new personal best of 7.80, which also qualified her for the 2014 World Indoor Championships where she took the gold medal running 7.80 a second time.
In 2015, Nia took a year off to give birth to her son.
She returned to the 2016 World Indoor Championships to successfully defend her gold medal. After winning, she carried her son on the victory lap.
Ali placed third in the 100 hurdles in a time of 12.55 at the 2016 United States Olympic Trials behind Team USA teammates Brianna Rollins, Kristi Castlin to qualify to represent the United States at the 2016 Summer Olympics in Brazil. Later that year she won the silver medal at the Olympics. The United States was the first country to win gold, silver, and bronze in the women’s 100 hurdles in one Olympics in 2016; this was also the first time American women achieved such a sweep in any Olympic event.