We is a first-person narrative that takes place in the 29th century. Its protagonist is D-503, an engineer and mathematician, who lives in an authoritarian city called the One State. He builds a ship that allows travelers to visit other worlds and rule over free people. He drafts a diary that explains to the locals why they need to be subjugated. In the diary, D-503 invokes "we" as a collective term to describe his city's mission of dominating so-called lower civilizations.

The ruling force known as the Benefactor founded the city after winning a war that lasted two hundred years. Within the society, leaders control nearly every aspect of a person's life except their sexual activity and creative time. Authorities use rationality and order to preserve societal stability.

As D-503 is recording in his diary, he begins to think for himself and feel emotions. He also falls in love with I-330—a female revolutionary who stirs passion and complex emotions within him. This complicates D-503's relationship with his lover, O-90.

I-330 convinces D-503 to participate in a revolt against the state, but they ultimately fail. The state executes I-330, and it also lobotomizes D-503 to ensure his complacency. D-503 is no longer a threat to the regime. A pregnant O-90 flees the city to live among the free people, where she will raise her and D-503's child.