The Love Hypothesis is a romance novel by Ali Hazelwood, published September 14, 2021 by Berkley Books. Originally published online in 2018 as Head Over Feet, a Star Wars fan fiction work about the "Reylo" ship between Rey and Kylo Ren, the novel follows a Ph.D. candidate and a professor at Stanford University who pretend to be in a relationship.^[2]

Originally published online in 2018 as Head over Feet, a Star Wars fan fiction work about the "Reylo" ship between Rey and Kylo Ren,^[3][4] the main characters were renamed Olive and Adam (the latter after Adam Driver) on the novel's physical publication, with all explicit Star Wars references cut, and the characters on the novel's cover illustration designed after Driver and Daisy Ridley.^[5][6]

The Love Hypothesis follows the main character Olive in trying to convince her best friend, Anh into thinking that her dating life is going great. In order to convince Anh, she pretends to date her professor, Adam. Olive and Adam try to convince everyone around them they are in love. But while convincing everyone, they forget that their feelings are supposed to be fake. How long will it take for Olive and Adam to realize that they don't want to pretend anymore?^[2]

• Olive Smith – A third-year biology PhD student at Stanford University who researches pancreatic cancer - the disease her mother died from. She fakes a relationship with Dr. Adam Carlsen to convince her friend she got over ex boyfriend. The book is written from her perspective.
• Dr. Adam Carlsen – A young professor who is described by his students as harsh and hypercritical. The university froze his research funds because they are worried he thinks of leaving to a different university, Adam agreed to fake a relationship with Olive to make the science department believe he plans to stay at Stanford.
• Anh Pham – Olive's best friend, pushes Olive to try new things with Adam without knowing their relationship is fake. Likes Jeremy, Olive's ex boyfriend.
• Malcolm – Olive's roommate and friend, gay, later end up dating Dr. Rodriguez.
• Dr. Tom Benton – Professor at Harvard University and Adam's friend. He offers Olive a spot at his lab when hearing about her research. Later he threatens and sexually harasses Olive and steals her research. He ends up getting fired from Harvard after Olive reports him.
• Dr. Holden Rodriguez – Adam's friend, gay, ends up dating Malcolm.
• Jeremy – Olive's ex boyfriend.

The Love Hypothesis is a New York Times best seller.^[7]

The book received a starred review from Library Journal^[8] and positive reviews from Entertainment Weekly,^[9] Shelf Awareness,^[10] and Publishers Weekly.^[11] Kirkus Reviews provided a mixed review.^[12]

In 2021, the book was a finalist in the Goodreads Choice Awards for Romance, coming in second place behind People We Meet on Vacation with 683 fewer votes out of 435,858 votes total.^[13]

In October 2022, it was announced that a film adaptation of the novel is in development from Bisous Pictures.^[14][15][16]