[1] Julia Kern was born in Berkeley, California and grew up in Waltham, Massachusetts.

Individually, a 9th place in the sprint classic at the 2017 Junior World Championships in Soldier Hollow was her best result.

She participated in the 2019 World Championships in Seefeld, Austria, where she finished 19th in the 15 km skiathlon and 23rd in the individual sprint.

On 21 December 2019, Kern was on a World Cup podium for the first time in her career, finishing third in a sprint freestyle in Planica, Slovenia.

At the FIS Nordic World Ski Championships 2023, Kern and Jessie Diggins won bronze in the team sprint.