Orton Gillingham is an approach that was developed in the 1930s by Samuel Orton, a neuropsychiatrist, and Anna Gillingham, an educator and psychologist, for people with dyslexia.
Orton Gillingham (OG) is not a curriculum or a program, although there are curricula and programs based on the Orton Gillingham approach. There are even some companies that use “Orton Gillingham” in their name. These companies may offer a scope and sequence and other tools to support the OG approach, but they are not and do not claim to be curriculum companies. Instead, they aim to provide professional development about the rules and structures that govern the English language, and about how to most effectively teach those rules and structures to all children.