Marek Edelman (Yiddish: מאַרעק עדעלמאַן; 1919 or 1922 – October 2, 2009) was a Polish political and social activist and cardiologist. As a Jew, Edelman was the last surviving leader of the Warsaw Ghetto Uprising. Long before his death, he was the last one to stay in the Polish People's Republic despite harassment by the Polish United Workers' Party authorities.

Before World War II, he was a General Jewish Labour Bund activist. During the war he co-founded the Jewish Combat Organization (ŻOB). He took part in the 1943 Warsaw Ghetto Uprising, becoming its leader after the death of Mordechaj Anielewicz. He also took part in the 1944 Warsaw Uprising.

After the war, Edelman remained in Poland and became a noted cardiologist. From the 1970s, he collaborated with the Workers' Defence Committee and other political groups opposing the regime's ruling PZRP party. As a member of Solidarity, he took part in the Polish Round Table Talks of 1989. Following the peaceful transformations of 1989, he was a member of various centrist and liberal parties. He also wrote books documenting the history of wartime resistance against the Nazi German occupation of Poland.

Details of Marek Edelman's birth are not known for certain; sources give two possible years of birth, either 1919 in Homel (present-day Belarus), or in 1922 in Warsaw. His father, Natan Feliks Edelman (died 1924), was a member of the Socialist Revolutionary Party (his father's brothers, also Socialist Revolutionaries, were executed by the Bolsheviks). His mother, Cecylia Edelman (died 1934), a hospital secretary, was an activist member of the General Jewish Labour Bund, a Jewish socialist workers' party. When Edelman's mother Cecylia died, he was 14 years old, and was looked after by other staff members at the hospital where she had worked in Warsaw, the city he always called home. He said in 2001: "Warsaw is my city. It is here that I learned Polish, Yiddish and German. It is here that at school, I learned one must always take care of others. It is also here that I was slapped in the face just because I was a Jew."

As a child, Edelman was a member of Sotsyalistishe Kinder Farband (SKIF), the Jewish Labour Bund's youth group for children.

In 1939 he joined and became a leader in Tsukunft (Future), the Bund's youth organization for older children. During the war, he restarted these organizations inside the Warsaw Ghetto.

The defiance and organization of the Bund made their mark on Edelman. As conditions for Jews worsened in the 1930s, Bund members preferred to challenge the mounting antisemitism rather than flee. Edelman later said: "The Bundists did not wait for the Messiah, nor did they plan to leave for Palestine. They believed that Poland was their country, and they fought for a just, socialist Poland in which each nationality would have its own cultural autonomy, and in which minorities' rights would be guaranteed."

In 1939, after the German invasion of Poland Edelman found himself confined—along with the other Jews of Warsaw—to the Warsaw Ghetto. In 1942, as a Bund youth leader he co-founded the underground Jewish Combat Organization (Żydowska Organizacja Bojowa, ŻOB). In the Warsaw Ghetto Uprising of April–May 1943, led by Mordechaj Anielewicz, Edelman was one of the three sub-commanders and then became the leader after the death of Anielewicz.