The American Guild of Organists, or AGO, is a national organization of church and concert organists in the USA. It is divided into regions and chapters, and publishes a monthly magazine, The American Organist. Membership is not limited to professional organists, but is open to anybody with an interest in organ music.

The AGO holds national conventions every two years, and regional conventions in the years when it does not hold national conventions. It sponsors a number of education programs, including the "Pipe Organ Encounters," which are targeted at introducing young keyboard players to the organ.

The AGO also issues several professional certificates and designations upon completion of the appropriate exams and membership in good standing in a Guild chapter: the Service Playing Certificate, Colleague (CAGO), Choir Master (ChM), Associate (AAGO) and Fellow (FAGO).