Wicklow based Daniel Day-Lewis has become the first man to win the Best Actor Academy Award three times.
He was presented with the Oscar for his starring role in Lincoln, which was directed by Steven Spielberg, at the Oscars ceremony in Los Angeles last night.
He paid tribute to his wife, the author and director Rebecca Miller, and tearfully dedicated the award to his mother, the late actress Jill Balcon.
Accepting his award from Meryl Streep, an emotional Day-Lewis told the audience: "I really don't know how any of this happened. I do know that I have received so much more than my fair share of good fortune in my life and I'm so grateful to the Academy for this beautiful honour."
Christoph Waltz won Best Supporting Actor for Django Unchained, his second Oscar for his performance in a Quentin Tarantino film.
Anne Hathway walked away with the Best Supporting Actress award for her role in Les Misérables.
Tarantino won the Best Original Screenplay Oscar - also his second - for his script for the film.
The award for Best Foreign Film went to Amour; Searching for Sugar Man won Best Documentary Feature and Brave was named Best Animated Feature.
Adele and producer and co-writer Paul Epworth won the Best Original Song Oscar for their Bond theme Skyfall.
Actor in a Leading Role
Daniel Day-Lewis in Lincoln
Actor in a Supporting Role
Christoph Waltz in Django Unchained
Actress in a Leading Role
Jennifer Lawrence in Silver Linings Playbook
Actress in a Supporting Role
Anne Hathaway in Les Misérables
Ang Lee for Life of Pi
Music (Original Score)
Mychael Danna for Life of Pi
Music (Original Song)
Adele Adkins and Paul Epworth for Skyfall from Skyfall
Animated Feature Film
Mark Andrews and Brenda Chapman for Brave
Claudio Miranda for Life of Pi
Jacqueline Durran for Anna Karenina
Malik Bendjelloul and Simon Chinn for Searching for Sugar Man
Documentary Short Subject
Sean Fine and Andrea Nix Fine for Inocente
William Goldenberg for Argo
Foreign Language Film
Makeup and Hairstyling
Lisa Westcott and Julie Dartnell for Les Misérables
Rick Carter (Production Design) and Jim Erickson (Set Decoration) for Lincoln
Animated Short Film
John Kahrs for Paperman
Live Action Short Film
Shawn Christensen for Curfew
Per Hallberg and Karen Baker Landers for Skyfall and Paul NJ Ottosson for Zero Dark Thirty
Andy Nelson, Mark Paterson and Simon Hayes for Les Misérables
Bill Westenhofer, Guillaume Rocheron, Erik-Jan De Boer and Donald R Elliott for Life of Pi
Chris Terrio for Argo
Quentin Tarantino for Django Unchained