This study assessed the effect of Ownership Structure on Informativeness of Accounting Earnings of listed Deposit Money Banks in Nigeria. Ownership structure is proxied with Managerial ownership, Institutional ownership and Ownership concentration, while Informativeness of Accounting Earnings is proxied using Fan and Wong (2002) model. The study used a purposive stratified sampling technique to filter out banks that do not satisfy the criteria set out for inclusion thereby arriving at the sample size of ten (10) listed Deposit Money Banks in Nigeria out of twenty one (21). Secondary data source was used which were extracted from the Annual reports and accounts of the sampled Banks from 2006-2012. Multiple Regression, fixed and random effect analysis were adopted in the study.The findings revealed that, Managerial Ownership is negatively and significantly related to Earnings Informativeness, while Institutional Ownership and Ownership Concentration are positively and significantly related to Earnings Informativeness of listed Deposit Money Banks in Nigeria. It is recommended amongst others that those who are interested in the reported earnings as a basis for their investment decisions should look up to both Institutional Ownership and Ownership Concentration in those banks as they empirically guarantee the reliability of the Banks reported Earnings.