Which of these actors did not win an Oscar for playing multiple roles in a film?
Correct answer: Peter Sellers

humbeldywump
no fair, dr jeckyl and mr. hyde is 1 role

Deborah
I loved Lee Marvin in Cat Ballou. It was one of the first movies I saw in a movie theater.

SQinfoNUTS
only just paid to the character that Peter Sellers played of the wheelchair-bound former Nazi. In the movie three days of the Condor starring Robert Redford. You can't miss this guy.

BadAssChard
Twas a give away Peter Sellers didn't win an Oscar