Early childhood educators are increasingly asked to support the alphabet knowledge development of children enrolled in their classrooms. Children in the same classroom, however, often show vastly different alphabet learning needs. Moreover, recent research suggests that some letters are more difficult to learn. These facts run counter to one-size-fits-all whole-class instructional approaches, which typically provide the same instruction to all children and for all letters. The purpose of this article is to encourage early childhood educators to move beyond whole-class approaches and instead provide alphabet instruction that is aligned with current emphases on assessment-driven decision making and differentiated instruction. The article reviews the importance of alphabet knowledge with respect to theory, research, and the current educational context, summarizes recent research concerning children's alphabet knowledge development, and provides a framework in which assessment guides differentiated alphabet instruction, along with empirically-validated practices for such instruction.