Joseph David Lykken (/ˈlɪkən/ LIK-ən) is an American theoretical physicist at the Fermi National Accelerator Laboratory and, from July 1, 2014 to Sept 6, 2022, he was the Deputy Director of Fermilab.

He is the son of David T. Lykken, noted psychologist, behavioral geneticist, and twin researcher.

As a member of the CMS collaboration, he was co-author of the Higgs boson discovery paper,[7] and with Maurizio Pierini, Chris Rogan, and Maria Spiropulu, developed a new set of kinematic variables ("razor") targeting the discovery and characterization of new physics at the LHC.

Since 2018 he has been a member of the Quantum Communications Channels for Fundamental Physics (QCCFP) project, supported by the QuantISED program of the U.S. Dept.

[8] Accomplishments of this project include the first laboratory demonstration of traversable wormhole teleportation, using a Google Sycamore quantum processor.