[1] In 2021 Samuel Firewu finished fourth in the Men's 3000 metres steeplechase at the 2021 World Athletics U20 Championships in Nairobi.

[4] In August 2022, he finished as runner-up to compatriot Samuel Duguna to win the silver medal in the 3000 metres steeplechase at the 2022 World Athletics U20 Championships in Cali, Colombia.

[5] Samuel Firewu set a new personal best time of 8:10.57 at the Diamond League event in Monaco, in July 2023.

[11] He finished fourth in the 3000m steeplechase on 19 May 2024 at the 2024 Meeting International Mohammed VI d'Athlétisme, [12] and second at the 2024 BAUHAUS-galan Diamond League event in Stockholm.

[13] He competed at the 2024 Summer Olympics in Paris in the 3000 metres steeplechase, finishing in sixth place in the final.