Weltklasse Zürich (English: World Class Zurich) is an annual, invitation-only, world-class track and field meeting at the Letzigrund in Zürich, Switzerland, generally held at the end of August or beginning of September. Previously one of the IAAF Golden League events, it now serves as a final of the Wanda Diamond League, alongside Memorial Van Damme between 2010 and 2019. In 2021, Welklasse Zürich will serve as the sole final of the Diamond League. One of the first large-scale international athletics events (outside the Summer Olympics), it is sometimes referred to as the one-day Olympics. Weltklasse Zürich first took place on 12 August 1928. In the beginning, the meeting was nicknamed by the public the "Nurmi meeting" after the most admired and celebrated participant at the time, Paavo Nurmi. On 21 June 1960, on the Letzigrund track, Armin Hary became the first human to run the 100 m dash in 10.0 seconds.

UBS has supported Weltklasse Zürich as its main sponsor since 1981. Other sponsors are Vaudoise Assurances, Migros, Le Gruyère Switzerland, Medica, Omega, Swiss, Lexus, Erdgas and Puma.