The country singer became a break-out star in 1992 with the song, which quickly became one of the most-hated sing-along tunes ever - but he knew he could always count on Cash to back him up.
And in an interview with Queen Latifah on her new chat show, he reveals that just months after the song was released, the music legend took note of Cyrus' success, and personally extended him a warm welcome to the country music community.
Cyrus explains, "In June of 1992, he wrote a handwritten letter that basically said it was good to be reminded where all good things come from - from almighty God above. And he said that I reminded him of his buddy Elvis Presley.
The letter read: "36 years ago, I was working with Elvis and saw him take the same kind of flak you're taking now. Congratulations on the way you're handling it all. In your case, as in Elvis', the good outweighs the bad. Let 'em have it. I'm in your corner."
Cyrus continued, "It was a great source of strength at the time and I always loved Johnny Cash. To this day, I'm his number one fan."
It's fascinating to look at the life of Johnny Cash from a new angle, even...