The composition of America's teaching force has perilously lagged behind the country's increasingly diverse student body. Currently, more than 50 percent of the K-12 student body in public schools in the United States is made up of individuals of color. This change reflects broader demographic shifts that have been taking place in the US over the past several decades. However, looking at the make-up of the teaching force in America's schools, you will see a different picture. Today, only about 18 percent of teachers are individuals who identify as African American, Latinx, Asian, Native American, or other nonwhite groups. In addition, while we see high numbers of attrition for all teachers across the board, teachers of color (TOC) leave the teaching profession at higher rates. The tenuous state of diversity in America's teaching workforce has implications for the country's education overall, as well as for the growing numbers of students of color. This paper reviews the current literature that addresses the lack of teacher diversity in U.S. schools, focusing on four areas: (1) The overall picture of the state of diversity, or lack thereof, in the country's teacher workforce; (2) The key issues contributing to the "leaky" pipeline of individuals of color in the teaching profession; (3) The central challenges around the retention of TOC in their schools and the teaching profession in general; and (4) Promising practices in the field that provide hope and impetus for future change.