The Zero Day cast features Robert De Niro as George Mullen, Lizzy Caplan as Alexandra Mullen and Jesse Plemons as Roger Carlson. This info article contains minor spoilers and character details for Eric Newman, Noah Oppenheim and Michael Schmidt’s 2025 Netflix miniseries. Check out more cast guides in Vague Visages’ Know the Cast category.

Zero Day explores the aftermath of a cyberterrorism attack in the United States. As a former U.S. president named George Mullen leads an investigative committee, he worries about his mental health. The narrative follows the main protagonist as strategizes against various colleagues, including his own daughter. Here’s every actor and character in Zero Day.

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Zero Day Cast: Robert De Niro as George Mullen

Character Profile: A former U.S. president known for rallying bipartisan support. He leads an investigative commission after a cyberterrorism attack. George keeps on eye on various colleagues while researching a podcaster’s connection to a militia group.

De Niro’s Resume: Johnny Boy in Mean Streets (1973), Vito Corleone in The Godfather Part II (1974), Travis Bickle in Taxi Driver (1976), Jake La Motta in Raging Bull (1980), Max Cady in Cape Fear (1991)

Read More at VV — Know the Cast: ‘Apple Cider Vinegar’

Zero Day Cast: Lizzy Caplan as Alexandra Mullen

Character Profile: George’s daughter. She is a congresswoman who works as the chair of an oversight committee. Alexandra gets implicated in a cyberterrorism plot.

Caplan’s Resume: Janis Ian in Mean Girls (2004), Marlena in Cloverfield (2008), Virginia Johnson in Masters of Sex (2013-16), Josie Buhrman in Truth Be Told (2019-20), Reagan Ridley in Inside Job (2021-22)

Read More at VV — Know the Cast: ‘No Good Deed’

Zero Day Cast: Jesse Plemons as Roger Carlson

Character Profile: George’s top aide. He is a recovering drug addict with numerous hedge fund pals. Roger hooks up with Alexandra.

Plemons’ Resume: Todd in Breaking Bad (2012-13), Val Dodd in The Master (2012), Ed Blumquist in Fargo (2015), George Burbank in The Power of the Dog (2021), Tom White in Killers of the Flower Moon (2023)

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Zero Day Cast: Joan Allen as Sheila Mullen

Character Profile: George’s wife. She worries about her husband’s mental health. Sheila believes that George needs a trusted ally.

Allen’s Resume: Pat Nixon in Nixon (1995), Elizabeth Proctor in The Crucible (1996), Hennessey in Death Race (2008), Nancy in Room (2015), Amanda Debusher in Lisey’s Story (2021)

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Zero Day Cast: Connie Britton as Valerie Whitesell

Character Profile: George’s chief of staff. She investigates a government hack. Valerie gave birth to George’s “love child” in the past.

Britton’s Resume: Nikki Faber in Spin City (1996-2000), Tami Taylor in Friday Night Lights (2006-2011), Rayna Jaymes in Nashville (2012-18), Diane in Seeking a Friend for the End of the World (2012), Nicole Mossbacher in The White Lotus (2021)

Read More at VV — Know the Cast: ‘Missing You’

Zero Day Cast: Bill Camp as CIA Director Lasch

Character Profile: The CIA director. He protects the U.S. government’s best interests. Lasch warns George about potential threats.

Camp’s Resume: 12 Years a Slave (2013), Dennis Box in The Night Of  (2016), Detective Garrity in Joker (2019), Mr. Shaibel in The Queen’s Gambit (2020), Raymond Horgan in Presumed Innocent (2024)

Read More at VV — Know the Cast: ‘Nobody Wants This’

Zero Day Cast: Dan Stevens as Evan Green

Character Profile: The host of “The Evan Green Show.” He is a podcaster with connections to Russia and Wall Street. Evan speaks out against George.

Stevens’ Resume: Matthew Crawley in Downton Abbey (2010-12), David in The Guest (2014), David Haller in Legion (2017-19), Beast in Beauty and the Beast (2017), John Dean in Gaslit (2022)

Read More at VV — Know the Cast: ‘Black Doves’

Zero Day Cast: Angela Bassett as President Evelyn Mitchell

Character Profile: The U.S. president. She gathers “decisive” information after a cyberterrorism attack. Evelyn maintains a close professional relationship with George but keeps him on a short leash.

Bassett’s Resume: Reva Styles in Boyz n the Hood (1991), Betty Shabazz in Malcolm X (1992), Tina Turner in What’s Love Got to Do with It (1993), Stella Payne in How Stella Got Her Groove Back (1998), Ramona in the MCU (2019)

Read More at VV — Know the Cast: ‘The Madness’

Zero Day Cast: Matthew Modine as Richard Dreyer

Character Profile: The Speaker of the House. He wants George to testify about a militia group. Richard colludes with various colleagues/friends in search of power.

Modine’s Resume: Pvt. Joker in Full Metal Jacket (1987), Dr. Ralph Wyman in Short Cuts (1993), William Shaw in Cutthroat Island (1995), Foley in The Dark Knight Rises (2012), Dr. Martin Brenner in Stranger Things (2016-22)

Read More at VV — Know the Cast: ‘A Man on the Inside’

Zero Day Cast: McKinley Belcher III as Carl Otieno

Character Profile: George’s Kenyan colleague from Baltimore. He is a former assistant attorney. Carl coordinates an investigation after a cyberterrorism attack.

Belcher III’s Resume: Agent Trevor Evans in Ozark (2017-22), Lighting Designer in Marriage Story (2019), Anthony Carter in The Passage (2019), Momodu “G Money” Gondo in We Own This City (2022), Ledroit in Eric (2024)

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The Zero Day cast also includes:

• Mozhan Navabi as Melissa Kornblau
• Jay Klaitz as Tim Pennington
• Cuyle Carvin as Agent Tom McCarthy
• TJ Lee as Doris
• Eden Lee as Angela Kim
• Alexis Cash as Mullen’s Aide — Allison
• Gaby Hoffmann as Monica Kidder
• Mark Ivanir as Natan
• Jackson Eick as Nick Mullen
• Ryan Spahn as Leon
• Ignacio Diaz-Silverio as Cesar Rocha
• Clark Gregg as Robert Lyndon
• Nikita Bogolyubov as Alexi Lebedev
• Jorge Luna as General Tom Myles
• Varak Baronian as Uri
• Charlotte Ewing as Lily Whitesell
• Merritt Janson as Aubrey

Q.V. Hough (@QVHough) is Vague Visages’ founding editor.