V'yacheslav Vasilovich Danilenko (born 1935, Ukrainian: Выячеслав Васильович Даниленко) is a Ukrainian physicist who specializes in the nanodiamonds, which he gained expertise during his time in the former Soviet program of nuclear weapons. In 2011, the IAEA investigators and the investigative report by the Washington Post leveled serious allegations on him as a "foreign expert" and accused him of being a central figure in the nuclear program of Iran after the Soviet collapse in 1991.