Computational Thinking (CT) is an increasingly relevant concept that researchers are promoting in formal learning contexts. In their mission to prepare teachers to integrate CT into K-12 schooling, teacher educators would benefit from understanding the different kinds of preconceptions of CT that their students bring to the classroom in order to design learning experiences that build upon that preexisting knowledge. In this systematic literature review of 24 articles, I aim to identify the different types of preconceptions that teachers hold around CT. Results show that teachers hold preconceptions that can affect how they define CT. Specifically, they can conflate CT with (1) technology integration, (2) computer science or programming, (3) other non-specific problem-solving strategies, and (4) "thinking like a computer". They also may hold preconceptions around teaching and learning CT. Specifically, the literature shows they believe CT is a difficult topic to understand that often cannot feasibly be integrated into K-12 education due to curriculum and instruction constraints. In this article, I identify this initial list of preconceptions, demonstrate their presence in the literature, and propose ways for teacher educators to build upon them without antagonizing "incorrect" initial definitions that teachers may hold. Implications and limitations of this work are discussed.