Barack Obama Joins Eli & Peyton on MNF, Manning's 'Dream Guest'

Eight months ago TMZ Sports asked Eli Manning who his "dream guest" was for the MNF's Manningcast ... and the 2x Super Bowl-winning quarterback told us it was Barack Obama.

Tonight, 44 joined Easy E and Peyton Manning during the 1st quarter of Monday Night Football ... proving, dreams do come true!

"Mr. President, Eli was approached by TMZ last year. They asked him "who is your dream guest on the show, and he said it was you. I assume you were watching TMZ and felt pressure to come on the show, right?" Peyton joked with B.O.

"I have to confess, TMZ is not on my remote really," President Obama responded, fibbing (we kid) ... “but, I was flattered when I heard about this, Eli."

"Thank you very much. But the main reason I’m on, I think is actually Cooper, he called me up, and after seeing him on those Caesar's ads I thought, how could I turn him down?”

And, it only took the Manning's about 250 days to lock down one of the most famous people in the world.

We talked to Eli in mid-February at a Super Bowl party in Los Angeles, when we asked about his pick for top guests.

“Maybe a President. Barack Obama would be pretty good," Manning told us, saying, "I think we can get him.”