Orton-Gillingham is an instructional approach intended for use with people who have difficulty with reading, spelling, and writing associated with dyslexia. It is most properly understood and practiced as an approach, not a method, program, system or technique. It is a powerful tool of exceptional breadth, depth, and flexibility.

The Approach is so named because of the foundational contributions of Samuel T. Orton and Anna Gillingham. Samuel Torrey Orton (1879-1948) a neuropsychiatrist and pathologist. He was a pioneer in focusing attention on reading failure and related language processing difficulties. He brought together neuroscientific information and principles of remediation. 

The Orton-Gillingham Approach is most often associated with a one-on-one teacher-student instructional model. Its use in small group instruction is not uncommon. Reading, spelling and writing difficulties are  the dominant focus of the approach.

The Orton-Gillingham Approach always is focused upon the learning needs of the individual student. Students with dyslexia need to master the same basic knowledge about language and its relationship to our writing system as any who seek to become competent readers and writers. However, because of their dyslexia, they need more help than most people in sorting, recognizing, and organizing the raw materials of language for thinking and use.