Catwoman first appeared as The Cat in Batman (DC, 1940 series) #1 (Spring 1940).
The character would be called The Cat-Woman or Catwoman beginning with issue #2 (Summer 1940).
Catwoman would not receive her alter ego of Selina Kyle until Batman (DC, 1940 series) #62 (December 1950).
First appearance of Catwoman of Earth-One in Detective Comics (DC, 1937 series) #203 (January 1954).
First appearance and death of Catwoman of Earth-Two in DC Super Stars (DC, 1976 series) #17 (November-December 1977).
Contessa Selina DiGatti of Earth 24 (Bombshells) first appeared in DC Comics: Bombshells (DC, 2015 series) #3 (December 2015). The Italian phrase "di gatti" means "of cats" in English.