The Rings of Power seemingly confirmed that the Stranger is Gandalf, but there are still hints that he could be another member of the Istari.

In the season finale, the mysterious, gray-haired wizard, played by Daniel Weyman, finally learns his name, acknowledging, “Gandalf. That’s what they’re going to call me, isn’t it?”

Surprisingly, Weyman hasn't actually been holding this secret for years. In fact, he was only told about the Gandalf reveal during the tail-end of filming The Rings of Power season 2 in Tenerife. "I actually found out when they were about to break down the internal sets for Tom Bombadil ['s] house," Weyman says.