Recently a group that was established in the 1990’s re-emerged on Facebook. The list is called The ME List on Facebook, and it is definitely worth joining irrespective of which country in which you reside. Although it is a closed group, you simply have to ask to join.
USA & CANADA
U.S.: The 1st Families for Early Autism Treatment has a large list of parent organizations.
Canada: Families for Early Autism Treatment of British Columbia also has a list.
International sites that are worth joining if you reside in the relevant country are:
This organization is called Applied Behavior Analysis Ireland (ABAI)
This organization is called Parents Education as Autism Therapists (PEAT)
This organization is called Parents for the Early intervention of Autism (Peach)
There are a couple of organizations that I found:
Autism Behavioural Intervention Queensland
Autism Behavioral Intervention Association, Inc. in Victoria