Yes — "it" is always capitalized in title case because it is a pronoun.
"It" is a pronoun and is always capitalized in title case. AP Style, Chicago Style, MLA Style, NYT Style, and AMA Style all capitalize pronouns as content words that carry substantive meaning in a title.
The two-letter length of "it" sometimes causes writers to confuse it with function words like "in" or "at." The distinction is grammatical: "it" is a pronoun, not a preposition or article, and is always capitalized.
APA Style, Wikipedia Style, and Sentence Case lowercase "it" in the middle of a title since those styles use sentence case across the board.
"It" appears in widely known titles — including the Stephen King novel — and is correctly capitalized as a pronoun under all title case style guides.
"It" is a personal pronoun and is capitalized in all title case styles. Pronouns are content words — they refer to nouns and carry substantive meaning — and style guides universally capitalize them in titles.