Audax is a Latin adjective meaning "bold, daring" and may be used to refer to:
- Audax (cycling), long distance endurance bicycle rides
- Audax Australia, an organisation that runs long distance randonnee] cycling events in Australia and New Zealand
- Audax Club Sportivo Italiano, a Chilean football club based in the city of Santiago
- Audax was a British warplane, made by Hawker.
- Rootes Audax, a family of cars from the Rootes Group including the Hillman Minx, Hillman Husky, Singer Gazelle and Sunbeam Rapier.
- Audax, Ditalcus and Minurus, was one of the assassins of the Lusitanian leader Viriathus during the Roman Conquest of Hispania
- St. Audax is a 3rd century saint who was martyred with Victoria and Anatolia.
- Audax was also an archbishop of Tarragona (Spain) in ca. 633, who assisted to the Fourth Council of Toledo.
- Audax Minor (1887-1979), racing columnist for The New Yorker