The main aim of this research study is to compare the Relationship Marketing Orientation (RMO) between public and private commercial banks in Sri Lanka. Thus, the findings of this study can possibly be useful to promote application of Relationship Marketing Orientation in both public and private banks in Sri Lanka. The theory of social exchange provides a theoretical base for this study. Trust, bonding, communication, shared value, empathy and reciprocity were considered as dimensions of the RMO. The data obtained from 1002 customers of Sri Lankan commercial banks were analyzed to test relevant hypotheses. The findings revealed that Relationship Marketing Orientation of private banks is significantly higher than that of public banks. In particular, in terms of individual dimensions of the RMO, Bonding, Shared Value and Empathy of the private banks seemed to be significantly higher than those of the public banks. Nevertheless, public banks were more trustworthy than private banks. Based on these findings, we have provided interesting implications and recommendations to the both private and public banks.