Throughout the first decades of the 20th century, eugenic ideas gained and enjoyed a substantial following in both academic and non-­‐academic circles around the globe. While many of the most prominent spokespeople for eugenics were scientific or medical practitioners, a substantial number of lay activists and enthusiasts also made significant contributions to the movement. These latter figures often found it easiest to exert influence in international organizations dedicated to the political campaign for eugenic social reform, and consequently most of the major groups most closely associated with the eugenics movement were actually headed or at least partially led by amateur enthusiasts through the 1920s and 1930s. Further, many of these non-­‐scientists initially gained their influence through significant financial contributions to scientific researchers working on eugenic studies and the same activist organizations they were leading. This paper will ‘follow the money’ and examine the financial underpinnings of the international eugenics movement in the first four decades of the 20th century to explore the influence of outside philanthropy on the development of eugenic science and social reform campaigns alike. The first major donor to the eugenics movement was Francis Galton himself, who endowed University College London’s eugenics chair in his will. Over the following decades a number of significant individuals from both the U.S. and Great Britain followed in Galton’s footsteps, making substantial personal contributions to research they believed would advance the cause of eugenic social reforms. Interestingly, several of these figures saw themselves as amateur researchers who had been excluded from the scientific establishment through the processes of academic professionalization that took place during the same period. It is clear that through financial contributions these figures hoped to secure themselves a role in determining the path eugenics would take despite their lack of academic qualifications. Finally, this paper will conclude by examining the responses of the scientific practitioners who received such funds to the efforts of their donors to direct research priorities from afar to argue that eugenics was always a contested terrain between scientific and non-­‐scientific voices.