From wikipedia...
Johnny Cash planted the seed for the song in the fall of
1955, while Perkins, Cash, Elvis Presley, and other Louisiana Hayride acts
toured throughout the South. Cash told Perkins of a black airman whom he had
met when serving in the military in Germany. He had referred to his military
regulation air shoes as "blue suede shoes." Cash suggested that Carl
write a song about the shoes. Carl replied, "I don't know anything about
shoes. How can I write a song about shoes?"
When Perkins played a dance on December 4, 1955, he noticed
a couple dancing near the stage. Between songs, Carl heard a stern, forceful
voice say, "Uh-uh, don't step on my suedes!" Carl looked down and
noted that the boy was wearing blue suede shoes and one had a scuff mark. Good
gracious, a pretty little thing like that and all he can think about is his blue
suede shoes, thought Carl.
Carl Perkins lead g, v / Jay Perkins acoustic g, background v / Clayton Perkins sb / W.S. Holland d.
Recorded December 19, 1955.