School choice dominated discourses within educational policy in the last year; some have even described 2021 as “the year of school choice.” School choice allows public education funds to follow students to the schools or services that best fit their needs. This is often summarized by its advocates as “funding students over systems.” Generally, school choice allows market forces to influence education by providing more competition in the education market. Teachers’ unions have fought against school choice measures for years, but what impact do they have? This undergraduate thesis compares 49 states to determine if the proportion of public school teachers in teachers’ unions in a given state serves as a proxy to measure the impact of unions and to discover whether teachers’ unions influenced whether a state passed new school choice legislation in 2021. By employing a binary logistic regression analysis, the results provide evidence that as the share of public school teachers who are union members increases, a state’s likelihood to pass new school choice legislation increases. This thesis gives a broad view of the impact teachers’ unions have on school choice at the state level, but more research detailing the ways unions leverage these effects and how politicians respond to teachers’ unions in their states would be valuable.