The Hollywood superstar scrawled the message - along with a heart doodle - while he was filming a stunt on top of the Burj Khalifa in Dubai for new flick, Mission: Impossible - Ghost Protocol.
“The only person who will ever see [the signature] is the guy who paints the building some day,” said the film's stunt co-ordinator Gregg Smrz.
The note was written 15 feet from the top of the 2,723 ft tall, 160-storey tower, the New York Post reports.
The building is more than double the height of New York's Empire State Building.
Cruise is seen dangling from the building as he reprises his role as spy Ethan Hunt in the latest instalment in the action movie franchise, due to hit screens in the US on December 21 and December 26 in the UK.