Anton Zeilinger (German: [ˈanton ˈtsaɪlɪŋɐ]; born 20 May 1945) is an Austrian quantum physicist and Nobel laureate in physics of 2022. Zeilinger is professor of physics emeritus at the University of Vienna and senior scientist at the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences. Most of his research concerns the fundamental aspects and applications of quantum entanglement.

In 2007, Zeilinger received the first Inaugural Isaac Newton Medal of the Institute of Physics, London, for "his pioneering conceptual and experimental contributions to the foundations of quantum physics, which have become the cornerstone for the rapidly-evolving field of quantum information". In October 2022, he received the Nobel Prize in Physics, jointly with Alain Aspect and John Clauser for their work involving experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.

Anton Zeilinger was born in 1945 in Ried im Innkreis, Upper Austria, Austria. He studied physics at the University of Vienna from 1963 to 1971. He received a doctorate from the University of Vienna in 1971, with a thesis on "Neutron depolarization measurements on a Dy-single crystal" under Helmut Rauch. He qualified as a university lecturer (habilitation) at the Vienna University of Technology in 1979.

In the 1970s, Zeilinger worked at the Vienna Atominstitut as a research assistant and later as an associate researcher at the Massachusetts Institute of Technology Neutron Diffraction Laboratory until 1979, when he accepted the position of assistant professor at the same Atominstitut. That year he qualified as a university professor at the Vienna University of Technology.

In 1981 Zeilinger returned to MIT, as an associate professor on the physics faculty, until 1983. Between 1980 and 1990 he worked as a professor at the Vienna University of Technology, the Technical University of Munich, the University of Innsbruck and the University of Vienna.

He was also the scientific director of the Institute for Quantum Optics and Quantum Information in Vienna between 2004 and 2013. Zeilinger became professor emeritus at the University of Vienna in 2013. He was president of the Austrian Academy of Sciences from 2013 till 2022.

Since 2006, Zeilinger is the vice chairman of the board of trustees of the Institute of Science and Technology Austria, an ambitious project initiated by Zeilinger's proposal. In 2009, he founded the International Academy Traunkirchen, which is dedicated to the support of gifted students in science and technology. He is a fan of the Hitchhiker's Guide To The Galaxy by Douglas Adams, going so far as to name his sailboat 42.

Zeilinger published one of the first realizations of quantum teleportation of an independent qubit. He later expanded this work to developing a source for freely propagating teleported qubits and quantum teleportation over 144 kilometers between two Canary Islands. Quantum teleportation is an essential concept in many quantum information protocols. Besides its role for the transfer of quantum information, it is also considered as an important possible mechanism for building gates within quantum computers.