The first paladins in Diablo lore were the rebellious founders of the Order of Paladins, which formed during the Zakarum Inquisition. They broke away from the Hand of Zakarum to protect the innocent and fight the Prime Evils instead of enforcing the inquisition’s brutality.

Lore context

The class is described as holy warriors, also called “Knights of the Faith,” trained with sword and shield to defend others. The order itself emerged from a rebellion inside the Zakarum ranks, so there isn’t a single named “first paladin” given in the sources I found; it’s more accurate to say the first paladins were that founding rebel group.

Simple answer

  • First paladins: the original rebel members of the Order of Paladins.
  • Named first paladin: not identified in the source material I found.

TL;DR

Diablo lore points to the founders of the Order of Paladins as the first paladins, and it does not clearly name one individual as the very first.