Macarthur or the Red Book is a 2007 novel by Filipino author Bob Ong. It is the sixth published work from Ong. As with all Bob Ong's published novels, it is notable for its use of contemporary street Filipino words. It is also notable for its departure from the usual Bob Ong formula of using humor to comment on the various ironies of Filipino culture. Instead, it offers a gritty, realistic look at life in a Philippine slum community.

The title is derived from a slang term for difficult-to-flush feces — a reference to Douglas MacArthur's famous promise, "I shall return".^{[citation needed]} The cover's background, mostly obscured by the bold typeset of the title and by the red color, depicts a toilet bowl.^{[citation needed]}