The 2021 Australian Open was a Grand Slam tennis tournament that took place at Melbourne Park, on 8–21 February 2021. It was the 109th edition of the Australian Open, the 53rd in the Open Era, and the first Major tournament of the year. It was originally scheduled for 18–31 January 2021, but was postponed by three weeks to February due to the COVID-19 pandemic. The event was part of the 2021 ATP Tour and the 2021 WTA Tour.

The 2021 WTA Tour was the elite professional tennis circuit organised by the Women's Tennis Association (WTA) for the 2021 tennis season. The 2021 WTA Tour calendar comprises the Grand Slam tournaments, the WTA 1000 tournaments, the WTA 500 tournaments, the WTA 250 tournaments, the Billie Jean King Cup, and the year-end championships. Also included in the 2021 calendar are the Summer Olympic Games, which were rescheduled from 2020.