The son of poor peasant farmers, his initial education was at St. Michael's (Anglican) School, in Owa-Alero, from 1958 to 1964, when he got his First School Leaving Certificate.
Okoh served in the Nigerian Army, being commissioned as a lieutenant in 1982, promoted to captain in 1986, then to major in 1991 and lieutenant-colonel in 1996, his current rank.