Jacques Derrida (/dɛrɪˈdɑː/; French: [ʒak dɛʁida]; born Jackie Élie Derrida; 15 July 1930 – 9 October 2004) was a French Algerian philosopher. He developed the philosophy of deconstruction, which he utilized in a number of his texts, and which was developed through close readings of the linguistics of Ferdinand de Saussure and Husserlian and Heideggerian phenomenology. He is one of the major figures associated with post-structuralism and postmodern philosophy although he distanced himself from post-structuralism and disavowed the word "postmodernity".

During his career, Derrida published over 40 books, together with hundreds of essays and public presentations. He has had a significant influence on the humanities and social sciences, including philosophy, literature, law, anthropology, historiography, applied linguistics, sociolinguistics, psychoanalysis, music, architecture, and political theory.

Into the 2000s, his work retained major academic influence throughout the United States, continental Europe, South America and all other countries where continental philosophy has been predominant, particularly in debates around ontology, epistemology (especially concerning social sciences), ethics, aesthetics, hermeneutics, and the philosophy of language. For the last two decades of his life, Derrida was Professor in Humanities at the University of California, Irvine. In most of the Anglosphere, where analytic philosophy is dominant, Derrida's influence is most presently felt in literary studies due to his longstanding interest in language and his association with prominent literary critics. He also influenced architecture (in the form of deconstructivism), music (especially in the musical atmosphere of hauntology), art, and art criticism.

Particularly in his later writings, Derrida addressed ethical and political themes in his work. Some critics consider Speech and Phenomena (1967) to be his most important work, while others cite Of Grammatology (1967), Writing and Difference (1967), and Margins of Philosophy (1972). These writings influenced various activists and political movements. He became a well-known and influential public figure, while his approach to philosophy and the notorious abstruseness of his work made him controversial.

Derrida was born on 15 July 1930, in a summer home in El Biar (Algiers), Algeria, to Haïm Aaron Prosper Charles (known as "Aimé") Derrida (1896–1970), who worked all his life for the wine and spirits company Tachet, including as a travelling salesman (his son reflected the job was "exhausting" and "humiliating", his father forced him to be a "docile employee" to the extent of waking early to do the accounts at the dining-room table), and Georgette Sultana Esther (1901–1991), daughter of Moïse Safar. His family was Sephardic Jewish (originally from Toledo) and became French in 1870 when the Crémieux Decree granted full French citizenship to the Jews of Algeria. His parents named him "Jackie", "which they considered to be an American name", although he would later adopt a more "correct" version of his first name when he moved to Paris; some reports indicate that he was named Jackie after the American child actor Jackie Coogan, who had become well known around the world via his role in the 1921 Charlie Chaplin film The Kid. He was also given the middle name Élie after his paternal uncle Eugène Eliahou, at his circumcision; this name was not recorded on his birth certificate unlike those of his siblings, and he would later call it his "hidden name".

Derrida was the third of five children. His elder brother Paul Moïse died at less than three months old, the year before Derrida was born, leading him to suspect throughout his life his role as a replacement for his deceased brother. Derrida spent his youth in Algiers and in El-Biar.

On the first day of the school year in 1942, French administrators in Algeria—implementing antisemitism quotas set by the Vichy government—expelled Derrida from his lycée. He secretly skipped school for a year rather than attend the Jewish lycée formed by displaced teachers and students, and also took part in numerous football competitions (he dreamed of becoming a professional player). In this adolescent period, Derrida found in the works of philosophers and writers (such as Rousseau, Nietzsche, and Gide) an instrument of revolt against family and society. His reading also included Camus and Sartre.

In the late 1940s, he attended the Lycée Bugeaud [fr], in Algiers; in 1949 he moved to Paris, attending the Lycée Louis-le-Grand, where his professor of philosophy was Étienne Borne. At that time he prepared for his entrance exam to the prestigious École Normale Supérieure (ENS); after failing the exam on his first try, he passed it on the second, and was admitted in 1952. On his first day at ENS, Derrida met Louis Althusser, with whom he became friends. A professor of his, Jan Czarnecki, was a progressive Protestant who would become a signer of the Manifesto of the 121. After visiting the Husserl Archive in Leuven, Belgium (1953–1954), he completed his master's degree in philosophy (diplôme d'études supérieures [fr]) on Edmund Husserl. He then passed the highly competitive agrégation exam in 1956. Derrida received a grant for studies at Harvard University, and he spent the 1956–57 academic year reading James Joyce's Ulysses at the Widener Library.