Pot Still
Zosimos of Panopolis documented the earliest known ancestor of the pot still in Roman Egypt during the late third or early fourth century.
Working in Panopolis, probably also drawing on Alexandria’s alchemical tradition, Zosimos described apparatus that heated a liquid in one vessel and carried its vapour through tubes into a separate receiver. His writings are among the oldest surviving technical accounts of distillation equipment, although this is a poor claim to having "invented" it, but it's the closest thing we have.
Zosimos credited an earlier experimenter, Maria, with important devices including the tribikos, a three-armed still designed for distillation. That makes her a plausible early contributor, but the exact dates and biography remain uncertain; leaving us with our uncredited, but loosely placed, origin.
The fourth-century apparatus was used for alchemical and laboratory work, not whisky or other modern spirits. Over later centuries, the alembic evolved into simpler heated vessels with condensers - the basic family of equipment now called pot stills - while the name pot still itself belongs to the devices that followed over a millennia later, that formed around, well, a pot for the heating of the liquid.
The pot still in concept was not invented to make alcohol - it was developed centuries earlier for alchemy and medicine. Its use for distilling drinkable spirits only emerged after roughly a thousand years of unrelated purposes.