Fans started arriving outside the BFI Imax in central London in the early hours of this morning to get a prime spot to see the action, and Cruise arrived before 7am to start signing autographs and posing for pictures.
The star told the crowd: "Thank you so much for being here at the earliest premiere ever."
Asked how he convinced the cast and crew to attempt the triple premiere for his new film, Edge Of Tomorrow, he said: "They love it, they wanted to do it. London, Paris, New York in one day, they're pumped about it, they're excited about it."
Cruise and his co-star Emily Blunt were in the capital for the first of three world premieres of Edge Of Tomorrow - a science fiction thriller in which they play soldiers fighting off an alien attack, only to be killed then forced to relive the battle over and over until they come closer to defeating their enemies.
He said he and director Doug Liman "loved that central concept", adding: "Doug and I really latched on to it because it allowed for that unique journey and a very unique kind of love story, something I hadn't seen before, so it was a lot of fun working on it."
Blunt, who gave birth to a daughter in February, said the lack of sleep had prepared her for the challenge of attending three events in one day.
She said: "I'm used to it so maybe I'll fare better than any of them."
She was full of praise for her co-star, saying: "He's got such a dynamic personality and it's really inspiring to be around because it was such a demanding shoot, so we needed that energy. He's fun, he's got such a self-deprecating attitude."