Aharon Katzir (Hebrew: אַהֲרֹן קָצִיר; born Aharon Katchalsky; September 15, 1914 – May 30, 1972)^[1] was an Israeli scientist who was known as a pioneer in the study of the electrochemistry of biopolymers.

Born 1914 in Łódź, Poland, he moved to Mandatory Palestine in 1925, where he taught at the Hebrew University in Jerusalem. There, he adopted his Hebrew surname Katzir. He was a faculty member at the Weizmann Institute of Sciences, Rehovot, Israel as well as at the department of medical physics and biophysics at UC Berkeley, California.

He was murdered in a terrorist attack at Ben Gurion International Airport in 1972 in which 26 people were killed and 80 injured.^[2] His younger brother, Ephraim Katzir, became the President of Israel in 1973.

• In 1961, Katzir was awarded the Israel Prize, in life sciences, together with his pupil, Ora Kedem.^[3]
• The State of Israel issued a postage stamp in memory of Katzir.
• The Katchalsky crater on the Moon is named after him.
• A series of Hebrew lectures is held at Tel Aviv University in memory of Katzir, organized by his son Avrahm, a professor of physics. It is named: In the Crucible of the Revolution (BeKur HaMahapecha), alluding to a popular book Katzir wrote about scientific progress. It has featured lectures by Nobel Prize laureates Daniel Kahneman and Aaron Ciechanover, and philosopher Hilary Putnam.^[4]
• A center at the Weizmann Institute of Science is named after Katzir, as well as public schools in Tel Aviv and elsewhere.^[5]
• A scholarship program of the Israeli Ministry of Defense is also named after him.

• Katchalsky, Aharon; Curran, Peter F. (1965). Nonequilibrium Thermodynamics in Biophysics. Harvard University Press.

• List of Israel Prize recipients
• Science and technology in Israel