Amaryllis Fox Kennedy (born Amaryllis Damerell Thornber; September 22, 1980) is an American former Central Intelligence Agency officer, government official, campaign manager, tech entrepreneur, and writer serving since 2025 in various positions in the Trump Administration, including at the United States Intelligence Community and the White House.

Kennedy is the Deputy Director of National Intelligence for Policy and Capabilities and Associate Director for Intelligence and International Affairs at the Office of Management and Budget (OMB). She is also a member of President Donald Trump's Intelligence Advisory Board (PIAB). She served in the CIA from 2002 to 2010.

Kennedy wrote a memoir about her time in the CIA, Life Undercover: Coming of Age in the CIA, published by Knopf Doubleday in 2019. She hosted the six-episode Netflix documentary series The Business of Drugs, released in 2020. She was a campaign manager for her father-in-law Robert F. Kennedy Jr.'s 2024 independent presidential campaign.

Amaryllis Fox Kennedy was born in New York City as Amaryllis Damerell Thornber. Her mother, Lalage Damerell, is a retired English actress. Her father, Hodson Thornber, was an economist. Her mother has since married businessman and film producer Steven Rales. When Fox Kennedy was eight years old, her friend Laura died in the bombing of Pan Am Flight 103 over Lockerbie, Scotland. She said of the event in an interview, "I remember being very, very overwhelmed by the loss and my dad intervened and said, 'you have to understand the forces that took her or they will drown you'." She has said the moment catalyzed her increased awareness of current events and geopolitical conditions.

Growing up in Washington, D.C. and London, Fox Kennedy attended the National Cathedral School beginning in eighth grade and graduated in 1998; she attended The American School in London during tenth grade. She completed undergraduate studies at the University of Oxford in 2002. She has said that while at Oxford, she rebuffed approaches from the Secret Intelligence Service. Before Fox Kennedy's last year at Oxford, the September 11 attacks took place while she was visiting family in Washington, D.C.; subsequently, she decided to pursue a master's degree in conflict and terrorism at the Walsh School of Foreign Service. For her master's thesis, Fox Kennedy developed an algorithm intended to identify local terrorist safe havens, which attracted the CIA's attention.

In 1999, at age 18, Fox Kennedy clandestinely recorded an interview for the BBC with the Burmese leader Aung Sang Suu Kyi, then under house arrest. To arrange the meeting, Fox Kennedy worked with a local dissident journalist with whom she communicated via taped messages inside the water tank of a toilet at a café in Rangoon. Her intent in the trip had been to make a secret recording of planned pro-democracy protests on September 9. A book, In the Quiet Land, was set to be published in 2002, with film rights optioned to Golden Square Pictures and screenplay by Nick Thomas.

Fox Kennedy became one of the CIA's youngest female officers at age 22, assigned to "non-official cover", entailing living abroad with a fake identity and no diplomatic protection. She has said she assumed the cover of an art dealer and focused on preventing terror organizations from acquiring weapons of mass destruction. After eight years at the agency, Fox left the CIA in 2010.

In 2012, Fox Kennedy founded Mulu, a social commerce platform that enabled users to share product recommendations and direct a percentage of affiliate proceeds to either themselves or a charity of their choice. That year, Mulu was featured in Mashable's list of "10 Hot Startups Changing the Face of Retail".