Although many south-east Asians and/or Polynesians had prior visits, who was the first European to record sighting the Australian coastline?

The Dutch ship Duyfken (Little Dove)

Captained by Willem Janszoon, the Dutch ship Duyfken (Little Dove) recorded the first confirmed European sighting of Australia in 1606 and was the first of many expeditions to chart parts of the Australian coastline.

https://federationstory.com/first-confirmed-european-sighting-of-australia/

To supplement the information in the response above, Willem Jansz and his crew of the Duyfken not only sighted what was to become Australia, but they actually stepped foot on Australian soil at the Pennefather River on Cape York Peninsula. In 1616, Dirk Hartog discovered and mapped part of the Western Australian coast. By 1618, the first accurate representations of the coast of Australia appeared on European maps.
https://www.dcceew.gov.au/parks-heritage/heritage/publications/great-southern-land-maritime-exploration-terra-australis