Eight foreign language films have been nominated for Best Picture to date:As a side thought, is this the first and only time a foreign language film has been nominated for Best Pic? I can't think of any others but I have a goldfish-style memory.
Grand Illusion (French, 1938)
Z (French, 1969)
The Emigrants (Swedish, 1972)
Cries and Whispers (Swedish, 1973)
Il Postino (Italian/Spanish, 1995)
Life is Beautiful (Italian, 1998)
Crouching Tiger, Hidden Dragon (Mandarin Chinese, 2000)
Letters from Iwo Jima (Japanese, 2006)
Slumdog Millionaire is in Hindi for about a third of its running time.