The women's 400 metres at the 2013 World Championships in Athletics was held at the Luzhniki Stadium on 10–12 August. Heats started with Christine Ohuruogu leading 6 others under 51 with an exceptionally fast 50.20. 50 seconds was the order of the semifinal day. Six finalists dipped under 50, and Kseniya Ryzhova was lucky Amantle Montsho had gapped the first semi with the leading qualifier of 49.56. Ryzhova cruised in with a 50.48 to be the second automatic qualifier. Five others ran personal bests attempting to qualify.