Mr Diya, a retired lieutenant general, died earlier on Sunday in Lagos at the age of 79.
President Muhammadu Buhari on Sunday mourned the passing of Oladipo Diya, who served as Chief of General Staff from 1993 to 1997 and Vice Chairman of the Provisional Ruling Council in 1994.
The President, in a statement by his spokesperson, Femi Adesina, in Abuja paid tribute to Mr Diya's bold and courageous career in the Nigerian military.
Mr Diya, a retired lieutenant general, died earlier on Sunday in Lagos at the age of 79.
He hailed from Odogbolu in Ogun State.
Mr Diya, who was born on 3 April 1944 in Odogbolu, Ogun State, died on Sunday in Lagos.
Mr Buhari lauded the deceased for his dedicated service to the country as General Officer Commanding, 82 Division, Commandant, of National War College (1991-1993), Chief of Defence Staff and Military Governor of Ogun from January 1984 to August 1985.
He recalled that the late Mr Diya was known for his brilliance, exceptional organisational skills and discipline, and he displayed these virtues in the important roles he held in office as a military officer.
The president saluted the former chief of general staff for his love, belief and loyalty to the country he cherished so much and fought gallantly on the frontlines to defend her unity.
Mr Buhari, who extended heartfelt condolences to Diya's family, friends and colleagues, prayed that "Diya's soul finds rest with his Creator, and may his contributions to the nation never be forgotten."
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
President-elect Tinubu mourns Diya
Also, the President-elect, Bola Tinubu, has sent his condolences to the family of Mr Diya.
Mr Tinubu while expressing his sadness over the passing of the retired general in a statement on Sunday in Abuja, praised his contributions to national development and the military institution.
The president-elect, who is currently on vacation in London and would be in Saudi Arabia for Umrah (Lesser Hajj) before returning to the country, said the news of Mr Diya's death came to him as a shock.
"I send my heartfelt condolences and sympathy to his immediate family, especially his wives and children.
"Gen. Diya lived a remarkable life of a soldier and he made his mark in the military where he served our country diligently as military governor of Ogun State and in the various military positions he held.
"He rose to the enviable position of Chief of General Staff and second in command to the Head of State, he served meritoriously," Mr Tinubu said.
He noted that as much as he could, Mr Diya played a stabilising role during one of the most turbulent periods in the country's life in the aftermath of the June 12, 1993, presidential election.
The president-elect said the deceased would be remembered for his patriotism and service to the nation.
He condoled with Governor Dapo Abiodun and the people of Ogun, Mr Diya's home state and prayed to Almighty Allah to comfort his family and those he left behind and to grant his soul eternal rest.
NAN
