The Australasian Intervarsity Debating Championships (known colloquially as "Australs") is an annual debating tournament for teams from universities in the Australasian region. It is one of the world's largest debating tournaments, second only in size to the World Universities Debating Championship (WUDC), the European Universities Debating Championships (EUDC) and one of the largest annual student events in the world. Australs follows the Australia-Asian Debating format (three speakers plus replies), rather than the British Parliamentary Style used at WUDC. It is held every year in early-July under the auspices of the Australasian Intervarsity Debating Association (AIDA). The host university is selected a year before at a meeting of the Council of the Australasian Intervarsity Debating Association.

The best speaker of the tournament is awarded the "Martin Sorensen Trophy", and the best speaker of the Grand Final is awarded the "Jock Fanselow Cup".

The most recent edition of Australs was held by EduDrift in partnership with Chulalongkorn University. The tournament was held in person for the first time since 2019 and hosted in Krabi, Thailand. The current champions are Isabella Freeland, Eugene Bakker and Charlie Ryan of the University of Sydney Union.

This section does not cite any sources. (August 2021)

Since the inaugural tournament at the University of Sydney in 1975, Australs has continually expanded the scope of its participants, now attracting around 300 competitors each year from around the Asia-Pacific region. Australs was significantly modernised in 1993 when a new constitution was introduced by then AIDA President. The Constitution provided for standard rules of debate and adjudication, and provided for extended voting rights for non-Australian and New Zealand participants. Currently teams come from Australia, Bangladesh, China, Hong Kong, India, Indonesia, Japan, Malaysia, New Zealand, Pakistan, Singapore, South Korea, Thailand, Russia and the Philippines.

Prior to the inception of the AIDA in 1990, there were occasional problems with the administration and rule-format for Australs, as the running of the tournament was left to the host university, with a meeting of all Universities at the end of the competition. There was little ongoing supervision of the hosts, and adjudication standards varied widely.

In 1992 an affirmative action requirement was introduced to ensure that at least one third of each University's contingent must be female, unless the circumstances could be justified. This was prompted by the poor representation of female debaters at Australs. In 1990 only 8% of all speakers eligible to make the finals at Australasian championships were female, although women were over-represented as adjudicators. In 1991, the year before the introduction of the affirmative action requirement, the first women's meeting was held to discuss ways to combat the problem. At that time the participation rate had risen to 21%, with the introduction of a number of universities as first-time participants. Few women were represented in the finals, however. The intention behind the introduction of the rule was that it would encourage universities to promote debating to a large number of potential members and train their debaters before they attended Australs. It was also thought that this would encourage a greater diversity of speaking styles, rather than what was seen as a very aggressive style by a number of very successful and talented Australian male debaters, and this would benefit all debaters and universities.

• World Universities Debating Championship
• North American Debating Championship
• United Asian Debating Championships