Mika Laaksonen[3] Oluwatobiloba Ayomide "Tobi" Amusan OON // ⓘ (born 23 April 1997)[4] is a Nigerian track and field athlete who specialises in the 100 metres hurdles and also competes as a sprinter.

[5][6] She is also the current Diamond league champion in the 100 metres hurdles having won the final in 12.33 seconds (+1.8 m/s) achieving a winning streak in 2021, 2022 and 2023.

In 2021, Amusan became the first Nigerian athlete to win a Diamond League title as she took the 100 m hurdles trophy, breaking the then-African record held by Glory Alozie in the process.

[9] In May 2023, Amusan earned Master of Arts degree in Leadership Studies and Sports Management at the University of Texas at El Paso, United States.

[21] At the 2018 Commonwealth Games in Gold Coast, Australia, 2015 world champion Danielle Williams seemed to be the favourite to take the title in the absence of Sally Pearson.

[23] This fulfilled a Nigerian tradition being 11th gold for Nigeria in the 100 m hurdles since Judy Bell-Gam triumphed at the inaugural edition of the championships in 1979.

In the semi-finals the following day, she equaled this personal best before placing fourth a few hours later in the final with a time of 12.49 s.[4] Amusan finished fourth at the delayed 2020 Tokyo Olympics with a time of 12.60 s.[4] She later competed in the Zürich Diamond League final event, which she won in a new African record of 12.42 s, breaking 23-years-old best of 12.44 s held by her compatriot Glory Alozie and becoming the first Nigerian to win a Diamond League trophy.

[7] In June, Amusan defended her 100 m hurdles title at the African Championships in Mauritius with a time of 12.57 s. She also competed in the women's 4 × 100 m relay to earn a second gold medal.

[30][31] She competed in her specialist event at the Lausanne Diamond Race meet later that month, finishing second with a time of 12.60 s, behind reigning Olympic champion Jasmine Camacho-Quinn.

Amusan wrapped up her long and successful 2022 campaign by winning 100 m hurdles at the Zürich Diamond League final event with a 12.29 s performance to retain her title.

[33][34] On 17 August 2023, the Disciplinary Tribunal found that Amusan had not committed an Anti-Doping Rule Violation of three whereabouts failures within a 12-month period and her provisional suspension was lifted.