Lillie Nordmann (born August 5, 2002) is an American competitive swimmer specializing in butterfly and freestyle events.

[15] Nordmann was named as one of the five captains for the contingent of swimmers to represent the United States at the 2019 World Junior Championships, held at Danube Arena in Budapest, Hungary.

[18] The following day, she won the gold medal in the 200 meter butterfly with a time of 2:08.42, finishing over half a second ahead of the silver medalist in the event, Blanka Berecz of Hungary.

[21][22] While Nordmann had originally committed to starting at Stanford University in the autumn of 2020, she decided to defer her enrollment one year to 2021 due to the COVID-19 pandemic.

[25] Once she graduated from high school in the spring of 2020, she moved to and commenced training in California in anticipation of starting at Stanford University the following year.

[30] Starting off her collegiate career at Stanford University in the autumn of 2021, Nordmann was bestowed with the Stanford Cardinal women's swim and dive kickboard, a symbol of the spirit of the swim team that had formerly been in the possession of swimmers on the school team including Janet Evans and Katie Ledecky.

[31] On the second day of the 2022 Pac-12 Conference Championships, held in February at the King County Aquatic Center in Federal Way, Washington, Nordmann ranked 13th in the prelims heats of the 500 yard freestyle with a 4:47.13.

[33] On the second day of the 2022 NCAA Championships in Atlanta in March, Nordmann placed 31st in the prelims heats of the 500 yard freestyle with a 4:44.35.

[37] In the morning of day three, she swam a 1:43.02 in the prelims heats of the 200 yard freestyle and qualified for the final ranking sixth.

[39] In the prelims heats of the 200 yard butterfly on the fourth and final day, she tied for ninth with a time of 1:53.63 and qualified for the b-final.

[45] At the 2022 NC State GAC Fall Invitational in Greensboro, North Carolina, Nordmann placed third in the 100 yard freestyle with a personal best time of 48.45 seconds.