Asynchronous online discussions (AODs) are often used to promote critical thinking in online courses; however, recent research suggests that levels of critical thinking in discussions remain low. Furthermore, there is a lack of consensus in the literature about the definition of critical thinking and many of the existing studies focus on one specific cognitive construct. Therefore, it is unknown which instructional approaches have the strongest empirical support for promoting critical thinking across multiple cognitive constructs. The purpose of this article is to present a review of the literature related to instructional design and facilitation approaches that promote critical thinking in AODs across multiple cognitive constructs (cognitive domain, cognitive presence, knowledge construction, and perspective-taking). Design approaches, such as providing scaffolding and using a debate-based instructional approach, and facilitation approaches, such as using Socratic questioning and allowing students to lead discussions, are effective for promoting critical thinking. Additional research should be conducted to confirm the efficacy of case-based, problem-based, project-based, and role play instructional approaches and to reach a consensus on the definition of critical thinking as well as how critical thinking should be demonstrated and accurately assessed in AODs.