Minato knows Obito is Tobi

[USSJ Future Trunks]

when he talked to his son he referred to obito as 'masked man" so no he doesnt know who he is

 

[Nakamazi Itchigo]

Mmmm-maybe, kishi has trolled us a lot before so I wouldn't put it passed him lol

 

[Aimee Matsuyama]

He was referring to Madara, not Obito. Minato makes that statement in context of him asking if the masked man is Madara.

 

[B00m]

I think really nobody knows except for the people on the battlefield. That's crappy though, I want Minato to know it. No way Sasuke will find that out in his current conversation.

Orochimaru? If Kabuto knew, Orochimaru knows, right?

 

[Sarahmint]

I also predict this. Glad to know someone else thinks like me, but I would not call it a troll move, I'd call it withholding a reveal.

 

[Regulus]

Why would Minato think it's Obito? "Are you Uchiha Madara?" "No you couldn't be he is long dead" he is clearly talking about Madara.