In late 1965, during the midst of the Vietnam War, Daniel Ellsberg (Matthew Rhys) finds himself in Hau Giang Province alongside other soldiers, tasked with monitoring the battle's progress for his role at the Embassy. One night, while traversing the dark forest, they come under fire from unseen enemy snipers.
On his return flight, Ellsberg converses with Secretary of Defense Robert McNamara (Bruce Greenwood), sharing insights with the Chief of Staff about the disheartening realities of the war. Despite Ellsberg's declaration that "nothing has changed," McNamara grimly notes that this signifies a deteriorating situation. Upon arrival, McNamara misleads the press, asserting that conditions are improving.
Later, filled with determination, Ellsberg covertly exits the Pentagon armed with classified Vietnam War documents. In secrecy, he collaborates with colleagues to reproduce these papers. As he delves into their contents, he uncovers a troubling truth: four U.S. presidents—Truman, Eisenhower, Kennedy, and Johnson—had allegedly concealed significant facts about the war from both the public and the press.
Fast forward to 1971, Washington, D.C., where Kay Graham (Meryl Streep) is poised to take The Washington Post public. During a meeting with a colleague, she learns from Chief of Staff that President Nixon is displeased with her newspaper's potential coverage of his daughter's wedding. In a session with her managing editor, Ben Bradlee (Tom Hanks), she contemplates broadening their content to attract a diverse readership.
In a tense board meeting dominated by men, one associate, Arthur Parsons (Bradley Whitford), voices his skepticism regarding Graham's leadership, attributing his doubts partly to her gender and the stigma of being the widow of the former publisher, who tragically passed away under mysterious circumstances.
Furthermore, McNamara makes an unexpected visit to Graham at her residence, warning her that the following day’s paper might contain unfavorable coverage about him. Meanwhile, Bradlee dispatches an intern to the New York Times for insight into an impending report by journalist Neil Sheehan ([Michael Stuhlbarg]). The intern returns with intelligence that the Times is preparing a groundbreaking piece regarding McNamara.
As events unfold, The Times publishes its explosive story about the Pentagon Papers, revealing the government's extensive cover-up. During dinner with Times editor Abe Rosenthal, Graham learns that Nixon intends to take legal action against the publication.
Post journalist Ben Bagdikian (Bob Odenkirk) relentlessly pursues Ellsberg until they can meet in a motel where Ellsberg entrusts him with more than 1,000 printed documents. Excitedly, Bagdikian informs Bradlee, rallying fellow journalists such as Meg Greenfield (Carrie Coon) and Howard Simons (David Cross) to strategize about the impending story.
As they brace for possible legal repercussions, Bradlee enlists lawyers Roger Clark (Jesse Plemons) and Anthony Essaye (Zach Woods). Amid this turbulence, Graham shares her trepidations with her daughter Lally (Alison Brie), expressing her struggles in managing the publication while honoring her late husband’s legacy. Lally reassures her mother, providing much-needed support.
Despite the looming threat of litigation, Graham resolves to proceed with publishing the explosive story. The following day, The Post releases its front-page article, sparking a domino effect that compels other newspapers to follow suit.
Graham finds herself in the Supreme Court as the stakes rise for both The Post and The Times. When a call comes in at The Post announcing that the court has ruled in their favor, Greenfield triumphantly reveals a quote from a justice stating, > "the court rules in favor of the governed, not the governors."
In a moment of camaraderie, Bradlee meets Graham at the publishing station, and they stroll together, deep in conversation. Meanwhile, tensions bubble over in the White House as Nixon orders that anyone from The Post be barred from his presence. The culmination of these events leads to a critical encounter at the Watergate Hotel, where a guard discovers a break-in, setting the stage for further upheaval.
