The women's 400 metre individual medley competition of the swimming events at the 2023 Pan American Games were held on October 24, 2023, at the Aquatic Center in Santiago, Chile.

[1] Prior to this competition, the existing world and Pan American Games records were as follows: The highest eight scores advance to the final.

[2] The B final was held on October 24.

[3] The A final was held on October 24.

[3]