Peter Fonagy, CBE, FBA, FAcSS, FMedSci (born 14 August 1952) is a Hungarian-born British psychoanalyst and clinical psychologist.

[8] These inabilities to mentalize and regulate affect have implications for severe personality disorders, as well as general psychological problems of self-confidence, and sense of self.

[10] He and Anthony Bateman proposed a new way to treat BPD in their book Psychotherapy for borderline personality disorder: mentalization-based treatment.

[11] Mentalization-based treatment (MBT), rooted in attachment theory, is based on the idea that people with borderline personality disorder mainly lack a reliable capacity to mentalize, which is caused by an absence of contingent and marked mirroring during development.

[12][13] In the 2024 Birthday Honours, Peter Fonagy was appointed a Commander of the Order of the British Empire (CBE) for services to mental health care for children and young people.