The women's 800 metre freestyle competition at the 2023 World Aquatics Championships was held on 28 and 29 July 2023.

[1][2][3] Prior to the competition, the existing world and championship records were as follows.

[4] The heats were started on 28 July at 12:13.

[5] The final was held on 29 July at 21:23.

[6]