It has become commonplace to say that, in the past, international governance has been legitimated mainly, if not exclusively, by its welfare-enhancing ‘output’. There has been very little research, however, on the history of legitimating international governance by its output to validate this point. In this essay I begin to address this gap by inquiring into the origins of output-oriented strategies for legitimating international organizations. Scrutinizing the programmatic literature on international organizations from the early 20th century, I illustrate how a new and distinctive account of technocratic legitimation emerged and in the 1920s separated from other types of liberal internationalism. My inquiry, centring on the works of James Arthur Salter, David Mitrany, Paul S. Reinsch and Pitman B. Potter, explores their respective conceptions of ‘good functional governance’, executed by a non-political international technocracy. Their account is explicitly pitched against a notion of ‘international politics’, perceived as violent, polarizing, and irrational. The emergence of such a technocratic legitimation of international governance, I submit, needs to be seen in the context of societal modernization and bureaucratization that unfolded in the first half of the 20th century. I also highlight how in this account the material output of governance is intimately linked to the virtues of the organizational form that brings it about.