Lenhydroproject (Russian: Ленгидропроект) is a major research and design institute for hydrotechnology and hydroelectric engineering based in St. Petersburg, Russia. Since 1993 it is incorporated as a " Lenhydroproject", part of RusHydro company.
The institute traces its history to the "Northern Russia hydro resources investigation team" established in April 1917 for research of rivers for the Ministry of Railroads.