The Lebedev Physical Institute of the Russian Academy of Sciences () is a Russian research institute in Moscow, specializing in physics. The institute was established in its present shape in 1934 by academician Sergey Vavilov. It moved to Moscow and was named after a Russian physicist Pyotr Lebedev the same year. It is also known as P. N. Lebedev Institute of Physics or just Lebedev Institute. In Russian it is often referred to by the acronym FIAN (äÃÂÃÂÃÂ) standing for "Physical Institute of the Academy of Sciences". The range of the research activities includes: laser technology, dark matter structure, nanostructures, superconductivity, cosmic rays, and gamma-astronomy. The institute developed a technique of crystallizing cubic zirconia (which was called Fianit in Russia, named after FIAN).
The institute has, among other research facilities, a particle accelerator: 1.2 GeV electron synchrotron called "Pakhra", located in Troitsk near Moscow (at the LPI's HEP department).
Andreyev Acoustics Institute is part of the Institute, and is named for Nikolay Andreyev.