On July 9, 2023, Nikki Hiltz won the 1500-meter race at the 2023 USA Track & Field Championships, adding their third USATF national championship this year and becoming the first openly nonbinary athlete to win a national title in track and field.
Hiltz dedicated their victory to the LGBTQIA+ community, saying they felt the community "needed a win" in light of the recent wave of anti-trans legislation being passed across the United States.
On July 15, 2023, Hiltz set a new American record in the mile, running 4:16.35 at the Monaco Diamond League. This broke the previous record 4:16.71, set by Mary Slaney in 1985. Hiltz's record-breaking performance has been met with widespread praise from the track and field community, and some have called it a "historic moment" for the sport.
Hiltz is currently training to represent Team USA at the 2023 World Athletics Championships, which will be held in Budapest, Hungary, in August, and to qualify for the 2024 Summer Olympics in France.