Onunkwo made the formal declaration at a meeting with the State Working Committee of the party at its office in Awka on Friday.
He said he was at the party Secretariat to inform them that he would join other aspirants in the APC primary election and expressed hope that he would clinch the ticket.
He tasked the party leadership on free, fair, just and acceptable primary in which every contestant would have equal advantage as only that would guarantee the support of others for the eventual winner.
Onunkwo said he was in the race to provide answers to the leadership question in Anambra assuring the party that he would serve the people above himself.