The singer - who rose to fame with the "Stairway to Heaven" legends - admits he doesn't think the group will ever get back together, but finds it "charming" people still care enough to ask.
He tells MOJO magazine, "Talking to me somewhere along the line, everything goes back to the biggest thing that ever happened to me (Led Zeppelin)."
"From your angle, you have to see it like that, but there ain't nothing really there about from speculation (sic)."
"We're 41 years into it now (since the band broke up). It's a very charming question, and it comes in all languages! But the conversation doesn't really go now, because that spaceship has (departed)."
Robert formed Led Zeppelin in 1968 alongside Jimmy Page, John Paul Jones, and late drummer John Bonham. They split in 1980 after his tragic death before reuniting in 1985, 1998, 1995, and 2007.
Robert Plant is currently gearing up to release his new album "Raise the Roof", a collaboration with Alison Krauss. The LP comes 14 years after their first joint album "Raising Sand" was released to critical acclaim.
He said in a previous interview, "We'd always wanted to do this. When the previous project came to fruition, she went off in one direction and I stayed in America and formed a group called the Band of Joy, and I went off on the road again. I love playing. As long as it's good fun, there's no better place to be."
"So we both did individual stuff, and we'd meet now and again or speak on the telephone like, 'How about this?' or 'Have you heard this song?' "