In 2019, U.S. Secretary of State Charlotte Field, portrayed by Charlize Theron, discovers from President Chambers that he has no intention to run for a second term. After a successful career as a TV star, Chambers is eager to transition into the film industry. Seizing the moment, Charlotte persuades him to endorse her as a potential presidential candidate. She is a Rhodes scholar and Pulitzer Prize winner, known as the youngest Secretary of State in U.S. history, tirelessly dedicated to her work, leaving little room for a personal life.
Katherine, the head of her polling team, encourages Charlotte to hire a humorous speechwriter to boost her public image and suggests she engage in a high-profile political romance, like dating the Canadian Prime Minister James Steward, to generate media excitement.
Meanwhile, New York journalist Fred Flarsky, played by Seth Rogen, discovers that his newspaper has been acquired by Parker Wembley, a powerful media mogul whose ethics are at odds with Fred’s values. Angered, he quits his job, only to find himself unemployed and despondent. Seeking solace, he turns to his successful best friend, Lance, who takes him to a charity event where Charlotte is in attendance. They share a moment of nostalgia, as she was once his babysitter and romantic interest during their teenage years.
As the two reconnect, Wembley interrupts, prompting Fred to criticize him for everything he represents. Inspired by Fred's columns, Charlotte decides to hire him as her speechwriter despite resistance from her manager Maggie, who dismisses Fred's appearance. Charlotte tasks Fred with crafting a speech for her upcoming meeting with King Gustav of the Swedish Royal family, using the opportunity to announce her ambitious environmental initiative called the Global Rehabilitation Initiative, which she intends to leverage in her presidential campaign.
While initially skeptical, Fred accepts the position but isn't convinced of Charlotte's commitment to genuine environmental change. During a summit, Charlotte is pressured to dilute her impactful environmental speech. When Fred urges her to remain true to her principles, she ultimately delivers a powerful address that wins acclaim, showcasing her integrity.
As they spend more time together under the guise of work, a bond develops, particularly during Charlotte’s 20-nation tour promoting her initiative. After a dangerous incident in Manila, they find refuge on a secluded island and their relationship deepens. However, Maggie warns them about the potential backlash they could face as a couple, suggesting Charlotte should align with someone like James Steward instead.
Tensions rise when Chambers pressures Charlotte to abandon plans to preserve certain trees to satisfy his allies. Following a moment of impulsiveness, Charlotte and Fred indulge in ecstasy, which leads to a hostage crisis involving a downed U-2 spy plane. Despite her inebriated state, Charlotte successfully negotiates the hostage’s release, boosting her approval ratings but incurring Chambers’ wrath for defying his orders.
Faced with manipulation from Chambers and Wembley, who leverage a compromising webcam video of Fred to coerce Charlotte, she reveals the blackmail scheme, intending to expose the corrupt dealings publicly. However, when Fred learns of the video, he feels betrayed and opts to end their relationship.
In New York, a talk with Lance prompts Fred to reconsider his rigid stance. As Charlotte prepares to announce her presidential candidacy, she surprises everyone by refusing to back down from her original plans, exposing the blackmail in front of the nation and preemptively releasing the video, which sensationalizes Fred's image across the media.
In a heartfelt reunion, Fred and Charlotte confess their love. At a press event, Charlotte introduces Fred as her boyfriend. In a historic turn of events, the couple marries in 2021, with Charlotte being sworn in as the first female president, while Fred embraces the role of "First Mister," taking her last name.
