As the consequences of climate change and global warming become ever more palpable, society as a whole urgently needs to reevaluate current practices. To this end, the implementation of autotrophic microorganisms in biotechnology may hold the key to cleaner and greener alternatives. In order to fully appreciate the complexity and potentiality of autotrophic microorganisms, an in-depth understanding of their metabolism and the pathways that govern it is paramount. In this chapter, autotrophy and its key subtypes (primarily photoautotrophy and chemolithoautotrophy) are defined, and their nuanced promise and current bottlenecks in biotechnology are introduced. Additionally, a short overview of key metabolic pathways is presented.