The 23-year-old Kenyan beat the previous women-only world mark of 14 minutes and 29 seconds set by Senbere Teferi of Ethiopia on September 12, 2021.
The Kenyan set the 5km world record at 14:13
"I came to Barcelona determined to better the world record as I felt capable of that… This world record means a lot for me, I can't believe it," said Chebet.
Her time was also quicker than the women's world record of 14 minutes 19 seconds set by Ethiopia's Ejegayehu Taye in a mixed race at the Cursa dels Nassos in 2021.
Ethiopian, Ejegayehu Taye’s 14 minutes and 21 seconds came in at second place, Kenya’s Lilian Kasait Rengeruk finished third with 14 minutes and 26 seconds, Joy Cheptoyek from Uganda also followed in fourth place with 14 minutes and 28 seconds, while Ethiopian, Medina Eisa rounded up the top five with 14 minutes and 40 seconds.