For nearly three years he has been in the news more for his compulsive partying, his fluctuating weight, and his on-off relationship with the South American model Gisele than for mere movie-making.
Last night all that changed as Leonardo DiCaprio swept into London's Leicester Square for the first time since February 2000 for the premiere of Gangs of New York, the long-awaited Martin Scorsese epic.
For his legions of fans, who last queued to see him at the premiere of The Beach, the near-freezing temperatures proved little deterrent as they waited in feverish anticipation for an actor who achieved rock-star status with the blockbuster Titanic - even if that star waned with his subsequent flops, The Beach and The Man in the Iron Mask.
Fans were also treated to the sight of an actor who has been off the screens for even longer than DiCaprio: the Oscar-winning Daniel Day-Lewis, whose performance in this movie has been so acclaimed that he is tipped for another Oscar nomination.
Jim Broadbent, who gained international recognition with his Oscar-winning performance in Iris, also appeared, as did the director himself, though the film's female star and love interest, Cameron Diaz, was absent.
For Leo's fans, the 28-year-old's appearance is just the first of two outings in London in three weeks. He is to return to the same venue on January 27 for the premiere of Steven Spielberg's Catch Me if You Can.
The two films were released just five days apart last month, in defiance of Hollywood convention that dictates rival films with the same leading man should not open simultaneously. But film experts believe the different genres - Gangs is a weighty historical epic and Catch Me a lighter caper - will ensure neither suffers at the box office, though Gangs, on show at fewer cinemas, has taken $47.1m (£29.4m) compared with Catch Me's $97.4m.
"They'll probably help each other and feed into each other," said Ian Freer, associate editor of the film magazine Empire. "They're so very different you wouldn't choose to go to one over the other."
Based on Herbert Astbury's 1927 book The Gangs of New York, Scorsese's $100m epic traces the violent foundations of the city in the 1860s and the rivalry between immigrant Irish and native gangs in the notorious Five Points slum area of lower Manhattan.
DiCaprio - who piled on 14kg (30lb) of muscle for the role - plays Amsterdam Vallon, an Irish hoodlum out to avenge the death of his father, murdered by Day-Lewis's character, Bill the Butcher, a notorious gang leader.
In Catch Me - for which DiCaprio was nominated at the Golden Globes - he stars as Frank Abagnale, a real-life charmer and conman who became one of America's most-wanted fraudsters after forging cheques worth millions of dollars and posing as a pilot, doctor and lawyer - all before his 21st birthday - while Tom Hanks stars as the FBI agent who hunts him down.
