All are considered strong contenders or even frontrunners for the Oscars, which will announce nominations on Thursday.
Other winners included "ParaNorman," best animated feature; "This Is Not a Film," best documentary; and "Holy Motors," best film not in the English language.
"This Is Not a Film" also won a special award for its filmmakers' "act of protest against the Iranian government." Other special awards went to composer Ennio Morricone and to Fandor and the "For the Love of Film" program for its restoration of the Hitchcock film "The White Shadow."
The Online Film Critics Society is one of the largest critics' groups, consisting of 186 critics from 19 countries around the world.
In the last 10 years, the OFCS has only agreed with the Oscar best-picture winner three times: "The Lord of the Rings: The Return of the King," "No Country for Old Men" and "The Hurt Locker." Last year the members opted for "The Tree of Life," which lost at the Oscars to "The Artist."
Best Picture: "Argo"
Best Director: Paul Thomas Anderson, "The Master"
Best Actor: Daniel Day-Lewis, "Lincoln"
Best Actress: Jessica Chastain, "Zero Dark Thirty"
Best Supporting Actor: Philip Seymour Hoffman, "The Master"
Best Supporting Actress: Anne Hathaway, "Les Miserables"
Best Original Screenplay: Wes Anderson and Roman Coppola, "Moonrise Kingdom"
Best Adapted Screenplay: Chris Terrio, "Argo"
Best Editing: Alexander Berner, "Cloud Atlas"
Best Cinematography: Roger Deakins, "Skyfall"
Best Animated Feature: "ParaNorman"
Best Film Not in the English Language: "Holy Motors"
Best Documentary: "This Is Not a Film"