The Spandau Ballet star and the Kids in America hitmaker teamed up to put on an acoustic show on a jumbo jet for fans, pals and British Airways staff at 43,000 feet (13,000 metres).
The duo, along with other 1980s acts including Bananarama and Go West, beat the previous record of 42,080 feet (12,825 metres) held by James Blunt.
Hadley says. "I'm very excited to be in the Guinness Book of Records, it's quite an amazing feat to be part of."
Passengers also set a second world record by performing the highest-ever routine to dance music sensation Baauer's track Harlem Shake.
The stunt took place as part of the U.K.'s annual Comic Relief charity fundraiser.