Mark Rylance received the supporting actor honour for Steven Spielberg's Bridge Of Spies.
Asif Kapadia's film Amy - which depicted the troubled life of the late singer Amy Winehouse - was named documentary of the year.
Brooklyn star Saoirse Ronan, who is nominated for the Best Actress Oscar for her role, was named British/Irish actress of the year.
Game Of Thrones star Maisie Williams, 18, accepted the young British/Irish performer award for her lead role in The Falling.
Oscar nominee Benjamin Cleary claimed the inaugural British/Irish short film of the year award for his unconventional love story Stutterer.
Here is the full list of winners for the 36th London Critics' Circle Film Awards:
• Film of the year - Mad Max: Fury Road
• British/Irish film of the year - 45 Years
• Actor of the year - Tom Courtenay (45 Years)
• Actress of the year - Charlotte Rampling (45 Years)
• Supporting actor of the year - Mark Rylance (Bridge Of Spies)
• Supporting actress of the year - Kate Winslet (Steve Jobs)
• Director of the year: George Miller (Mad Max: Fury Road)
• Screenwriter of the year - Josh Singer and Tom McCarthy (Spotlight)
• British/Irish actor of the year - Tom Hardy (Legend, London Road, Mad Max: Fury Road, The Revenant)
• British/Irish actress of the year - Saoirse Ronan (Brooklyn, Lost River)
• Young British/Irish performer of the year - Maisie Williams (The Falling)
• Documentary of the year - Amy
• Dilys Powell award for excellence in film - Sir Kenneth Branagh
• Foreign language film of the year - The Look Of Silence
• Philip French award for breakthrough British/Irish film-maker - John Maclean (Slow West)
• British/Irish short film of the year: Stutterer
• Technical achievement award: cinematographer Ed Lachman (Carol)
- PAA