ok, i know this is such an old debate but i think i might have found some proof in the anime that the 4th hokage is narutos father.
in one of the episodes, they close up on baby naruto when he was just born and he is being held by someone. in my opinion the clothes of that mystery person are the traditional red/white robes that a hokage wears... and the hokage at the time was the blond dude
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