In profile: 2014 Oscar winners
A look at the best actor winner and his fellow nominees at the 86th Academy Awards.
WINNER: MATTHEW McCONAUGHEY
Nominated for: Dallas Buyers Club
The character: Rodeo bull rider Ron Woodroof is a stereotypical redneck who is diagnosed HIV positive in 1986, and told he will probably die within 30 days. He soon discovers the drugs he needs are not approved for use in the US and begins smuggling them into Texas, both for his own use and to sell to others.
Oscar record: McConaughey, a former romcom lead who successfully reinvented himself as a character actor, has yet to be nominated for an Oscar.
The critics said: "Recently, McConaughey has given exploratory, strikingly intelligent performances in a wide variety of roles... And now, in Dallas Buyers Club, as the real-life Ronald Woodroof, he does work that is pretty much astounding." David Denby, The New Yorker
Age: 39 (but he will be 40 by the time the Oscars ceremony takes place in March)
Nominated for: American Hustle
The character: Con man Irving Rosenfeld makes his money selling forged and stolen art, until the FBI persuade him to join a sting operation targeting public corruption. Loosely based on the 1978 Abscam affair, Bale went to great lengths to play Rosenfeld, piling on 43 pounds and shaving his head to give him a realistic comb over.
Oscar record: Bale won best supporting actor in 2011 for playing boxer Dicky Eklund in biopic The Fighter, also directed by American Hustle's David O Russell.
The critics said: "Bale has undergone another of his famous physical transformations for the role, donning some truly terrible hair and a grotesque pot belly for the part. There's more than a little of Robert De Niro in his portrayal, with a couple of distracting mannerisms contributing a lot towards that overall impression." Mark Harrison, Den of Geek
Nominated for: Nebraska
The character: Retired mechanic Woody Grant falls for a piece of junk mail announcing he has won a million dollars and sets off on foot from Billings, Montana to collect his money.
Oscar record: It has been a while since Dern was up for an Academy Award. The last time he was in contention was in 1979, when his role in Coming Home gained him a best supporting actor nomination.
The critics said: "As the complex lost soul who can be at once endearing and infuriating, he slips perpetually between irascibility and incoherence, focusing just long enough to exasperate those around him. It's a rich and rewarding role into which Dern duly sinks his teeth." Mark Kermode, The Guardian
Nominated for: The Wolf of Wall Street
The character: Jordan Belfont, a hugely wealthy stockbroker whose hedonistic high life is funded by crime and corruption. The film is based on Belfont's own memoirs, who served 22 months in prison after being convicted of fraud.
Oscar record: DiCaprio has been nominated three times but is yet to win an Academy Award. He earned a supporting actor nomination for his breakthrough role as an autistic teenager in What's Eating Gilbert Grape. His performance as Howard Hughes in The Aviator landed him a best actor nod in 2005 and in 2007 he was nominated for Blood Diamond.
The critics said: "The DiCaprio of Wolf seems loose and uninhibited and freed of premeditated mannerisms. In his fifth collaboration with Scorsese, he's a constant joy to watch... DiCaprio doesn't just play this part; he inhales it, along with everything else that goes up Belfort's nose and into his bloodstream." Scott Foundas, Variety.
Nominated for: 12 Years a Slave
The character: Solomon Northup is a a free black man from New York, who is abducted and sold into slavery in Louisiana in 1841. Shipped to the South, he is forced to work for a brutal slave master (Michael Fassbender) on a New Orleans plantation. The film is based on Northup's own account, written just five months after his release from slavery.
Oscar record: Ejiofor is new to Academy Awards voters this year.
The critics said: "An enormously talented English actor getting the right break at the ideal moment. In the film's early scenes, we watch Solomon stroll around his home town of Saratoga with his wife and children, and, Ejiofor moves with a gentle confidence that makes his later imprisonment seem not just inhuman, but illogical." Robbie Collin, The Telegraph