This article begins with the observation that the scope of federal trademark protection has experienced hypertrophic growth in recent decades. Over the course of this expansion, trademark law has become unmoored from its supposed ideological foundations, and come to encroach on an ever-wider array of important social goods, such as free speech and vigorous competition in the marketplace. I argue that two factors are primarily responsible for this state of affairs: (1) trademark law's idiosyncratic test for infringement liability, which produces a likelihood-of-confusion feedback loop that drives the continuous expansion of substantive trademark rights; and (2) federal trademark law's lack of a robust doctrinal safety valve of the sort found in copyright and patent law, without which judges have no normative foot to put down. To remedy this situation, I propose to equip judges with the equitable defense of “trademark misuse,” which has been repeatedly advocated by defendants and commentators, but not yet recognized by any federal court. In crafting the new doctrine, I first examine the respective paths of the copyright fair use, patent misuse, and copyright misuse defenses, and borrow the best aspects of each, while attempting to avoid each doctrine's flaws. I then look to the public policies underlying trademark protection, and design a multi-factor test that strives to achieve a balance between flexibility and predictability. It is my hope that this article will highlight the pressing need for the adoption of the trademark misuse defense, and that the federal courts will utilize my framework as a way of overtly and systematically attending to important normative considerations that trademark law cannot effectively address in its current form.