Kayinsola Ajayi (born 14 September 2004) is a Nigerian sprinter.

[1] From Ikorodu, he won both sprints at the 2021 Maltina School Games and set a personal best of 10.26 seconds for the 100 metres at the second AFN All-Comers meet at Yabatech Sports Center in 2022.

[3] He won a gold medal in the 100 metres at the 2023 African Athletics U20 Championships in Ndola, Zambia.

[7] He finished fourth in the 100 metres at the African Championships in Douala, Cameroon that month.

[9] He competed in the 100 metres at the 2024 Paris Olympics, where he reached the semi-finals.