The women's 100 metre backstroke competition at the 1999 Pan Pacific Swimming Championships took place on August 23–24 at the Sydney International Aquatic Centre. The last champion was Mai Nakamura of Japan. This race consisted of two lengths of the pool, all in backstroke. Records Prior to this competition, the existing world and Pan Pacific records were as follows: Results All times are in minutes and seconds. Heats The first round was held on August 23. Semifinals The semifinals were held on August 23. Final The final was held on August 24. References 1999 Pan Pacific Swimming Championships 1999 in women's swimming