Family: Married to English actress Charlotte Riley, 33, since last year (his second marriage). He has a six-year-old son, Louis, with ex-girlfriend Rachael Speed.
His Mad Max: Buff and gruff. He is a man of few words, but there is the hint of a soft heart under that steely exterior.
Career before Mad Max: Hardy was already a Hollywood A-lister, with big commercial films such as Inception (2010) and The Dark Knight Rises (2012) to his credit.
He is also a respected dramatic actor who began his career on the London stage and went on to star in a string of critically acclaimed indie dramas, including Locke (2013), Warrior (2011) and Bronson (2008).
But this is the first time he is headlining a big action film, which will likely spawn its own franchise-within-a-franchise if it does well.
Reputation on screen and off: Known for playing brooding, tortured characters and immersing himself in his characters with method acting techniques and drastic physical transformations, bulking up unrecognisably to play a notorious British prisoner in Bronson.
Off-screen, he has come across as slightly eccentric after giving a few rambling interviews to the press.
Age: 59. He was 23 when the first Mad Max hit cinemas and 29 when the third film came out.
Family: Was married to actress Robyn Moore for 31 years till their divorce in 2011. They have a daughter and six sons aged 16 to 35 and three grandchildren. He also has a daughter aged five with ex-girlfriend Oksana Grigorieva.
His Mad Max: With three films, there is more character development in Gibson's version. Compared with Hardy's, his appears more unhinged and vengeful.
Career before and after Mad Max: Gibson was an unknown when he filmed the first Mad Max. It was Mad Max 2, however, that launched his career in Hollywood. Gibson would go on to become one of its most bankable leading men, thanks to hits such as the Lethal Weapon cop comedies (1987- 1992). He also won recognition as a serious dramatic actor with the war movie Gallipoli (1981). In 1995, he directed and starred in the historical biopic Braveheart, which earned him the Oscars for Best Picture and Best Director.
Reputation on screen and off: Gibson is that rare actor who has excelled in both comedies and dramas, as well as making a successful transition to directing. Off-screen, he has appeared increasingly eccentric over the years and courted controversy with ill-advised comments, leading to accusations that he is racist, misogynistic and homophobic.
Who is the 'crazier' Max?
Mel Gibson's name is forever entwined with the Mad Max movies, which propelled the Australian actor to stardom in the 1980s.
After appearing in 1979's Mad Max, 1981's Mad Max 2: The Road Warrior and 1985's Mad Max Beyond Thunderdome - all massive box-office hits - it seemed a foregone conclusion that he would star in the fourth instalment, which writer-director George Miller began thinking about in the late 1990s.
But Mad Max: Fury Road ended up taking more than 12 years to get off the ground, during which time its star - who went on to win the Best Director and Best Picture Oscars for his historical drama Braveheart in 1995 - managed to destroy his reputation with various public relations disasters.
Eventually Gibson, who is now 59, also became too old for the part, says Miller while promoting the new film, which sees Max played by English actor Tom Hardy, 37.
"This movie took so long to get going that by the time all the planets aligned, Mel had hit a lot of turbulence in his life," says Miller, no doubt referring to the fallout from racist and homophobic remarks made by the actor over the years.
Also, the tale of Max, a rebel battling for survival in a dystopian wasteland, "was never meant to be a story about an older warrior", Miller says. "It was time for a new Mad Max, just like there have been several James Bonds."
Although Mad Max fans had hoped to see Gibson make a brief appearance in Mad Max: Fury Road, the director believes this would have undermined his goal of making it "a standalone film".
"A rumour went around that Mel might do a cameo, but we were really trying to make this world authentic and for the audience to be caught up in the experience on screen.
"So it didn't make sense to suddenly have Mel appear. That would just pull the audience out... It would be like seeing Sean Connery appear in a Daniel Craig-James Bond film."
Gibson has publicly given the movie and his successor his blessing, even posing for photographs with Hardy at the recent Los Angeles premiere.
But in an interview with Details magazine, Hardy said their first meeting was a little "awkward", although Gibson did wish him good luck with the role.
Still, after the meeting, Gibson rang up Hardy's agent and handed a backhanded compliment to the younger actor, who also has a reputation for eccentricity.
Hardy recalls: "He said, 'I think you found someone that's crazier than I am.'"
Alison de Souza