The American Philosophical Association is the main professional organization for philosophers in the United States. Founded in 1900, its mission is to promote the exchange of ideas among philosophers, to encourage creative and scholarly activity in philosophy, to facilitate the professional work and teaching of philosophers, and to represent philosophy as a discipline.
"The Ohio Philosophical Association has as its purpose the encouragement of "research in philosophy in the colleges and universities in Ohio." The membership comprises all those who teach philosophy in institutions which are members of the Ohio College Association and those who are members of this Association at the age of retirement. Also, all who pay dues are members." from website
SPEP is the Society for Phenomenology and Existential Philosophy, a professional organization devoted to supporting philosophy inspired by continental European traditions.