[3] Onoja was born on 10 August 1948 at Idekpa Okpiko, Ohimini local government in Benue State of Idoma origins.

[5] Onoja attended the Nigerian Defence Academy, Kaduna and the Mons Officer Cadet School, Aldershot, England.

[3] Onoja was Principal Staff Officer to General Ibrahim Babangida before being appointed military governor of Plateau State in July 1988.

[3] Onoja was a Governorship aspirant in the 2003 Benue State elections on the United Nigeria Peoples Party (UNPP) platform.

[3] He competed against incumbent David Mark in the People's Democratic Party (PDP) primaries to be candidate for Senator in Benue South in December 2006.

[11] In the bitter fight, Onoja went as far as signing an advertorial in a national newspaper that support former Benue governor George Akume.