Ordu Yardımlaşma Kurumu (OYAK) (English: Military Solidarity Institution), is a Turkish charity and military pension fund with around 470,000 members. The OYAK Holding Investment Subsidiary Group is one of the largest industrial groups in Turkey.
The group was the former owner of ING Oyak Bank, sold to ING Bank in 2007, and the Oypa supermarket chain. In 2012, it was rated BB+/stable by Standard & Poor's. The group co-owns car manufacturer Oyak-Renault and steel producer Erdemir. OYAK Group of Companies added Sagra to its structure in April 2021. OYAK is on the global coal exit list published by Urgewald because it owns İsken Sugözü power station.
