The women's 4 × 100 metre freestyle relay competition at the 1999 Pan Pacific Swimming Championships took place on August 22 at the Sydney International Aquatic Centre.

[2] This race consisted of eight lengths of the pool.

The first swimmer had to touch the wall before the second could leave the starting block.

[3] Prior to this competition, the existing world and Pan Pacific records were as follows: All times are in minutes and seconds.

Heats weren't performed, as only seven teams had entered.