Who was the first European to have been to the Southern hemisphere?

Willem Janszoon.


While many European explorers crossed the equator in the 15th and 16th centuries, Willem Janszoon is generally credited with the first recorded European landing in the Southern Hemisphere (Australia) in early 1606. Dutch explorer Abel Tasman was the first to reach Tasmania and New Zealand in 1642.

Key Explorers of the Southern Hemisphere:
Willem Janszoon (1606): Dutch navigator who, in the Duyfken, landed on the western side of the Cape York Peninsula in Australia, marking the first confirmed European landfall in the Southern Hemisphere.

Pedro Fernández de Quirós (1606): Portuguese explorer sailing for Spain who reached the New Hebrides (now Vanuatu).

Luis Vaez de Torres (1606): Navigated the strait between Australia and New Guinea, proving New Guinea was an island.

Abel Tasman (1642): Dutch explorer who discovered Tasmania (which he named Van Diemen's Land and was the first European to sight New Zealand.

https://www.google.com/search?q=first+European+to+visit+southern+hemisphere&oq=first+European+to+visit+southern+hemisphere+&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIHCAEQIRigATIHCAIQIRigATIHCAMQIRigAdIBCjExMDI0NmowajeoAhSwAgHxBecqurMYJHhT&client=ms-android-hmd-terr1-rso1&sourceid=chrome-mobile&ie=UTF-8#lfId=ChxjMe

Prior to landings in Australia, the Portuguese had many excursions that crossed the equator. Wikipedia suggests that it was Diogo Cão who first landed south of the equator.

In August 1482, Cão arrived at the Congo River mouth and marked it with a padrão erected on Shark Point, commemorating the Portuguese occupation. This padrão stood until 1642 when it was destroyed by the Dutch during their occupation of the Congo.[7]

Cão sailed up the great river for a short distance and [...] then proceeded south along the coast of present-day Angola where he erected a second padrão, probably marking the termination of this voyage, at Cabo de Santa Maria.[13°25?07?S 12°32?00?E].

https://en.wikipedia.org/wiki/Diogo_Cão