The 2021 Prefontaine Classic was the 46th edition of the annual outdoor track and field meeting in Eugene, Oregon, United States.

Held on 20-21 August at Hayward Field, it was the eighth leg of the 2021 Diamond League – the highest-level international track and field circuit.

The meeting was highlighted by American records from Athing Mu (in the women's 800 m) and Courtney Frerichs (in the women's 3000 m steeplechase, becoming the first American to run under 9 minutes).

[1] Sifan Hassan attempted the 5000 metres world record, but did not achieve it.

[2][3] Athletes competing in the Diamond League disciplines earned extra compensation and points which went towards qualifying for the Diamond League finals in Zürich.