The women's 4 × 100 metre medley relay event in swimming at the 2013 World Aquatics Championships took place on 4 August at the Palau Sant Jordi in Barcelona, Spain.
Records
Prior to this competition, the existing world and championship records were: ==Results==
Results
Heats The heats were held at 11:08. Final The final was held at 19:48. ==References==