Yes. At one point in time, Professor Dumbledore did possess all three of the Deathly Hallows. He had already owned the Elder Wand since 1945, which was the year he defeated Gellert Grindelwald in a historic duel. He had obtained the next Hallow when he collected the Gaunt ring from where it was hidden by Lord Voldemort as a Horcrux, which also contained in it, the Resurrection Stone. He obtained the third and final Hallow when he borrowed James Potter's Invisibility Cloak to study it.