Most Oscar nominated Best Picture films starred in - single year
According to Official Guinness Records,
In a single year, two actors have had roles in three films nominated for Best Picture. Of the ten films nominated for the title in 1940, Thomas Mitchell (USA) had starred in Gone with the Wind (USA 1939) as Gerald O'Hara, Mr. Smith Goes to Washington (USA 1939) as Diz Moore and Stagecoach (1939) as Dr. Josiah Boone. Of the five films up for monination for the 2002 Academy Awards, John C. Reilly (USA) had appeared in Chicago (USA/Can 2002) as Amos Hart, Gangs of New York (USA/Ger/It/UK/Neth) as 'Happy' Jack Mulraney and The Hours (USA 2003) as Dan Brown. Both men were nominated for their respective supporting roles in Stagecoach (for which Mitchell won) and Chicago.