Sustainability challenges call for a shift towards plant-based proteins. This paper aims to analyze the development of plant-based meat alternatives in Sweden with a focus on legitimation processes. We divide legitimation into cognitive, normative, pragmatic and regulative varieties, and argue that configurations of legitimacy shape the directionality of innovation. We integrate this conceptualization into an analytical framework based on the technological innovation systems approach and analyze data from 41 interviews and multiple secondary sources. The analysis shows that the development of plant-based meat alternatives has been driven by a supportive configuration of strong normative legitimacy for low climate impact, increasing cognitive legitimacy based on associations with meat-based diets, increasing pragmatic legitimacy ensuring profitability for producers and convenience for consumers, and low regulative legitimacy due to weak policy support. This has shaped directionality towards the development of highly refined products that mimic meat, rather than towards simpler plant-based products, which may bring sustainability benefits but require more substantial behavioral change. Our findings suggest that policymakers can influence all four kinds of legitimacy, but have an especially important role in actively targeting regulative legitimacy. Other stakeholders can shape cognitive, normative, and pragmatic legitimacy to propel plant-based meat alternatives in desired direction.