The jet left Senegal and flew some nine hours before it landed in Atlanta.
CBS News transportation correspondent Bob Orr reports the plane was Delta flight 35 from Johannesburg, South Africa to Atlanta, via Dakar, Senegal, and it landed at approximately 8:40 EST.
The body, believed to be a man's, was found frozen and in pieces amid the machinery of the wheel well, according to CBS affiliate WGCL-TV in Atlanta.
Orr reports that sub-zero temperatures and extreme oxygen deprivation would make it nearly impossible for a human to withstand any length of time in a passenger aircraft's wheel well.
Authorities believe the stowaway got inside the right main wheel well during the stopover in Senegal.
The FAA says Delta was notified that the stowaway might be inside the plane after the Boeing 767 was already well into its flight. Delta apparently made a decision that it was too late for the plane to turn around, reports Orr.