This literature review on high school capstone courses found that, while the idea of such courses has been around since the 1990s, such courses have not been widely implemented and virtually no research exists on their effectiveness. Nevertheless, several high schools around the country have implemented senior culminating projects in which high school seniors, under the direction of an advisor or mentor, undertake an in-depth project on a topic of interest, utilizing the knowledge gained throughout high school, and presenting their work to a panel of judges near the end of the senior year. Descriptions of these experiences can be found on district and school websites. At the same time, a relatively new concept of capstone courses developed in the last five years, fueled in part by the work of the American Diploma Project (ADP), which supports state efforts to ensure that all students are college and career ready. Two types of capstone course fall under this umbrella: (1) senior-year transitional courses designed to prepare students who are not quite college-ready to succeed in entry-level college courses; and (2) fourth-year mathematics capstone courses for students who have met college-ready benchmarks by the end of junior year. These types of capstone courses, unlike the culminating project, focus on a specific content area and are likely to be classroom-based. The three types of capstone experiences described in this review are similar in that they are designed to build on what students have learned in high school while also preparing them for the challenges they will confront beyond high school, whether in college or the workforce. With the current national focus on college and career readiness, it is likely that capstone projects and courses will become increasingly common across the nation. As this occurs, research such as that being conducted in Virginia is strongly needed to document the implementation and impact of these courses. (Contains 11 footnotes.)