The women's 400 metres at the 2016 IAAF World Indoor Championships took place on March 18 and 19, 2016. Nigerian born Oluwakemi Adekoya, a mercenary runner for Bahrain, came into these championships as only the seventh fastest in the world this year, but she made her mark with the fastest times in each round. In the final, she was about even with Quanera Hayes at the break, but as Hayes broke for lane 1, Adekoya made a beeline for the apex of the next turn, effectively closing the door and relegating Hayes and the rest of the field to run behind her. Hayes gathered herself and made one big push coming around the final turn, but Adekoya was able to hold her off. Hayes tried again coming off the turn but couldn't make any progress. As Hayes strained for the finish, she made a second strategi