The women's 400 metre freestyle event at the 1988 Summer Olympics took place on 22 September at the Jamsil Indoor Swimming Pool in Seoul, South Korea.

[1] Prior to this competition, the existing world and Olympic records were as follows; The following records were established during the length of the competition; Rule: The eight fastest swimmers advance to final A (Q), while the next eight to final B (q).

[2] [3]