Viện cơ mật

The Viện cơ mật or "Secret Institute" (chu Han 院機密, Chinese 機密院, established 1834) was the Privy Council and key mandarin agency of the royal court of Vietnam's final Nguyễn Dynasty at Huế, until the end of the dynasty in 1945.

Minh Mạng established the Viện cơ mật (Privy Council) along with the Nội Các Viên (Cabinet, Grand Secretariat) as the main agencies of the court's administration. The Privy Council, or Secret Institute, comprised four of the most senior mandarins.