Dr. Seuss' The Cat in the Hat is a 2003 American family comedy film directed by Bo Welch. It is based on the 1957 Dr. Seuss book of the same name. The film stars Mike Myers in the title role of the Cat in the Hat, and Dakota Fanning as Sally. Sally's brother (who is unnamed in the book and the 1971 TV special), Conrad, is portrayed by Spencer Breslin. The film is the second feature-length Dr. Seuss adaptation after the 2000 holiday film How the Grinch Stole Christmas.

Who is the actor cat in the hat? OK. Let's think. My stream of consciousness:
The relevant sentence in the passage is: The film stars Mike Myers in the title role of the Cat in the Hat, and Dakota Fanning as Sally. The answer is Mike Myers.