Alexander Tansman (Polish: Aleksander Tansman, French: Alexandre Tansman; 12 June 1897 – 15 November 1986) was a Polish composer, pianist and conductor who became a naturalized French citizen in 1938. One of the earliest representatives of neoclassicism, associated with École de Paris, Tansman was a globally recognized and celebrated composer.

Tansman was born and raised in Łódź, Congress Poland. His parents were of Lithuanian Jewish ancestry. His father Moshe Tantzman (1868–1908) died when Alexander was 10 and his mother Hannah (née Gourvitch, 1872–1935) reared him and his older sister Teresa alone.

Tansman later wrote:

[M]y father's family came from Pinsk and I knew of a famous rabbi related to him. My father died very young, and there were certainly two, or more branches of the family, as ours was quite wealthy: we had in Lodz several domestics, two governesses (French and German) living with us etc. My father had a sister who settled in Israel and married there. I met her family on my [concert] tours in Israel. ... My family was, as far as religion is concerned, quite liberal, not practicing. My mother was the daughter of Prof. Leon Gourvitch, quite a famous man.

Tansman explained his later Francophile tendencies:

I had always been attracted to French culture. I had a governess who instilled in us a love of France. My family was very Francophile; we often spoke French at home and we had a vast French library. Ordinarily, Eastern European musicians went to Germany to pursue their careers. As for me, I chose Paris and have never regretted it. Nevertheless, I have returned to Poland a number of times.

Among his first music teachers were Wojciech Gawronski (a student of Zygmunt Noskowski, Moritz Moszkowski and Theodor Leschetizky) and Naum Podkaminer (a student of Hermann Graedener and Richard Hofmann).

Although he began his musical studies at the Lodz Conservatory, his study was in law at the University of Warsaw. On January 8, 1919, Tansman won the first composers' competition held in independent Poland, and gave a series of concerts at the Warsaw Philharmonic in the following months. In the fall of 1919, encouraged by his mentors Ignacy Jan Paderewski, Henryk Melcer-Szczawinski and Zdzisław Birnbaum, Tansman decided to continue his musical career in Paris. The first artists he was fortunate to meet shortly after his arrival were Moritz Moszkowski and Sarah Bernhardt. In Paris, his musical ideas were appreciated, influenced and favoured by composers Maurice Ravel, Albert Roussel, Jacques Ibert, Igor Stravinsky, musicologists and critics Émile Vuillermoz, Boris de Schloezer, Alexis Roland-Manuel, Arthur Hoérée, conductors André Caplet, Gaston Poulet, Vladimir Golschmann. Though Arthur Honegger and Darius Milhaud tried to persuade him to join Les Six, he declined, stating a need for creative independence. Nevertheless, he was one of the earliest and leading representatives of neoclassicism, along with Stravinsky, Les Six, Sergei Prokofiev, Paul Hindemith, Alfredo Casella. He was also one of the most respected members of the international music group École de Paris, along with Bohuslav Martinů, Tibor Harsányi, Alexander Tcherepnin, Marcel Mihalovici, Conrad Beck.