He's Just Not That Into You is a self-improvement book written by Greg Behrendt and Liz Tuccillo that was published in 2004 and later adapted into a film by the same name in 2009.

The book is about dating and romantic relationships that was inspired by an episode of Sex and the City, "Pick-A-Little, Talk-A-Little", in which the character Miranda Hobbes asks Carrie Bradshaw's boyfriend, Jack Berger, to analyze the post-date behavior of a potential love interest.

The premise of the book, as stated in the title, tells women readers that if a man in whom you are interested is not making the effort to pursue you, he is simply "just not that into you."

[1] Ken Kwapis directed the film, which featured an all-star cast including Ben Affleck, Jennifer Aniston, Drew Barrymore, Kevin Connolly, Jennifer Connelly, Bradley Cooper, Ginnifer Goodwin, Scarlett Johansson, and Justin Long.

[2] Despite receiving mixed reviews from critics,[3] it was a box office success, grossing over $180 million worldwide.