Lobbying is both an essential part of our democratic process and a source of some of our greatest fears about dangers to that process. Yet when Congress, the public, and scholars consider loosening or, as is more often the case, tightening the restrictions on lobbying, they usually assume that everyone knows what activities are in fact “lobbying.” They therefore overlook the fact that multiple definitions of lobbying currently exist in the various federal laws addressing lobbying. This Article seeks to fill this gap by answering the question of how lobbying should be defined for purposes of the existing federal laws relating to lobbying. The Article first explores the three sets of applicable laws, which tax lobbying, disclose lobbying, and restrict lobbyists. This exploration reveals that all three sets of laws arise out of a common concern regarding the influence of interest groups on government actions. Drawing on the extensive research regarding how interest groups wield such influence, the Article then determines that this research strongly suggests that the vulnerability to interest group methods that raise the greatest concerns varies depending on the type of government actor that an interest group seeks to influence. The Article therefore proposes the adoption of single definition of lobbying that covers all direct attempts to influence government officials and employees in Congress and at the very highest levels of the Executive Branch, while excluding attempts to influence other types of government actors and to influence the public.