The first mover advantage is a common feature in organizational theory. The advantages associated with early market entrance are considered critical for the long term productivity of firms. Surprisingly, however, the importance of timing is rarely explored in studies of interest group and policy influence. In this paper, we therefore explore whether a first mover advantage also exists in lobbying and leads to more organizational influence on policy outcomes. To this end, we suggest a theory of mover advantages for interest group politics. We hereby argue that a first mover advantage should lead to more influence on policy outcomes. We argue that these advantages should especially apply when certain further conditions are met, meaning they depend on the resources groups can leverage, the ties they already have with policymakers and the position interest groups have in the broader network of interest groups. We test whether our suggested model accurately predicts the influence of interest groups regarding Covid-19 policies across 10 countries. Our findings based on survey responses from over 1400 interest representatives are important for understanding lobbying influence as a dynamic process, where the timing of strategies interact with organization-level factors.