There appears to be no singular founder. According to Suzanne M. Peloquin, in the first of her two-part article linked below:
In 1917, six persons gathered to found the National Society for the Promotion of Occupational Therapy: those attending the meeting at George Edward Barton and Dr. William Rush Dunton, Jr.'s invitation were Thomas B. Kidner, Isabel G. Newton, Susan C. Johnson, and Eleanor Clarke Slagle. (Peloquin 353)
There are two others considered as "near founders" and a good description of their various professions and roles in the subsequent sentences. The article should be read for a fuller understanding of the profession.
You can also read more about Occupational Therapists below at Ferguson's Career Guidance Center or the Occupational Outlook Handbook.
