Which of these actors has not played the part of Lex Luthor in a major motion picture?

Jackie Cooper has not played the part of Lex Luthor. He played the part of Perry White, Clark Kent's hot-tempered boss at the Daily Planet in Superman (1978).

Alexander Joseph "Lex" Luthor is a fictional supervillain appearing in American comic books published by DC Comics. Created by Jerry Siegel and Joe Shuster, Lex Luthor first appeared in Action Comics #23 (April 1940) and has since endured as the archenemy of Superman.

Lex Luthor is a wealthy, power-mad American business magnate, ingenious engineer, philanthropist to the city of Metropolis, and one of the most intelligent people in the world. A charismatic and well-known public figure, he is the owner of a corporation called LexCorp, with Mercy Graves as his personal assistant and bodyguard. He is intent on ridding the world of the alien Superman, whom Lex Luthor views as an obstacle to his megalomaniacal plans and as a threat to the very existence of humanity.

The character was ranked 4th on IGN's list of the Top 100 Comic Book Villains of All Time and as the 8th Greatest Villain by Wizard on its 100 Greatest Villains of All Time list. Luthor is one of a few genre-crossing villains whose adventures take place "in a world in which the ordinary laws of nature are slightly suspended". John Shea and Michael Rosenbaum portrayed the character in Superman-themed television series, while Lyle Talbot, Gene Hackman, Kevin Spacey, and Jesse Eisenberg have portrayed the character in major motion pictures.