Hayk Mkrtichi Grigoryan (Armenian: Հայկ Մկրտիչի Գրիգորյան; born September 15, 1976) is an Armenian jurist currently serving as a member of the Supreme Judicial Council of Armenia.

Hayk Grigoryan was born on 15 September 1976 in Yerevan in what was the former Soviet Union.

In 1997, Grigoryan was admitted to the Prosecutorial and Investigative Division of the Special Faculty of the Military University of the Russian Ministry of Defense.

In 2009 he graduated from the school and defended the thesis for PhD degree titled "Investigation of crimes committed by military personnel of the Armenian Military Forces during the armed conflicts".

In July 2018, he was appointed Chairman of the Investigative Committee of the Republic of Armenia.