["Strategic Management Journal, EarlyView. ", "\nAbstract\n\nResearch Summary\nThe conventional wisdom both in research and in practice is that entrepreneurs need co‐founders, as they bring crucial resources to new ventures. Yet, this same work also suggests that co‐founders introduce destructive conflict, potentially creating as many problems as they solve. Surprisingly, little work examines the counterfactual—that is, the conditions under which solo‐founding is a viable approach. In this paper, we address this gap. We perform two studies; one using data from Y Combinator's renowned accelerator program, and another using large‐scale data from Crunchbase. Across these studies, we find that the solo founder disadvantage is partially attenuated when the founder has either broad or deep experience, or both (i.e., “T‐shaped skills”). Overall, our paper contributes to the literatures on founding teams and strategic human capital.\n\n\nManagerial Summary\nCo‐founders are beneficial to startups because they bring needed skillsets, knowledge, connections, and other resources. At the same time, however, co‐founders also introduce the potential for interpersonal conflict between the entrepreneur and co‐founders. Thus, in some cases, co‐founders may create as many or more problems as they solve. Surprisingly, very little research examines solo founders. In this paper, we examine the conditions under which solo founding is a viable approach. We find evidence of multiple ways in which solo founders can begin to overcome their performance disadvantages and achieve performance closer to that of co‐founded ventures.\n\n"]