She appeared in 34 films in Hollywood and in Europe, including Saint Joan, Bonjour Tristesse, Breathless, Lilith, The Mouse That Roared, Moment to Moment, A Fine Madness, Paint Your Wagon, Airport, Macho Callahan, and Gang War in Naples.
She was also one of the best-known targets of the FBI COINTELPRO project. Her targeting was a well-documented retaliation for her support of the Black Panther Party in the 1960s.
Seberg died at the age of 40 in Paris, with police ruling her death a probable suicide. Romain Gary, Seberg's second husband, called a press conference shortly after her death where he publicly blamed the FBI's campaign against Seberg for her deteriorating mental health. Gary claimed that Seberg "became psychotic" after the media reported a false story that the FBI planted about her becoming pregnant with a Black Panther's child in 1970. Romain Gary stated that Seberg had repeatedly attempted suicide on the anniversary of the child's death, August 25.