Swimming at the 2018 European Aquatics Championships – Women's 4 × 100 metre medley relay

The Women's 4 × 100 metre medley relay competition of the 2018 European Aquatics Championships was held on 9 August 2018.

Records
Before the competition, the existing world and championship records were as follows.

The following new records were set during this competition.

Heats
The heats were started at 10:05.

Final
The final was held at 18:07.