Orthographic knowledge, or knowledge of spellings, word forms, and conventions of print, is a crucial skill underpinning a range of literacy skills. Despite its importance, orthographic knowledge receives relatively little attention in second language contexts, including in adult English as a second language (ESL) programs. This chapter provides an overview of orthographic knowledge, its ... [Show full abstract] development in first language (L1), and what is understood about orthography in second language (L2). The chapter then reports detailed results of a qualitative interview study in which current and former ESL instructors shared their experiences, practices, and perspectives on orthographic instruction and assessment, including the development and use of instructor-generated assessments. The chapter concludes with a summary of results and suggestions for ESL orthographic instruction and assessment.