The Oncology Nursing Society (ONS) is a professional organization of more than 33,000 registered nurses and other healthcare providers dedicated to excellence in patient care, education, research, and administration in oncology nursing. It's also the largest professional oncology association in the world.
ONS traces its origin to the first National Cancer Nursing Research Conference, supported by the American Nurses Association and the American Cancer Society (ACS) in 1973. Following this conference, a small group of oncology nurses met to discuss the need for a national organization to support their profession. Since its official incorporation in 1975, ONS has become a leader in cancer care. It has grown to include 224 chapters and 30 special interest groups. It provides information and education to nurses around the world. In addition, the Society plays an active role in advocacy activities at the local, state, national, and international levels. The achievement of the Society's vision and mission is predicated on a belief in six core values.

　　ONS members are a diverse group of professionals who represent a variety of professional roles, practice settings, and subspecialty practice areas. Registered nurses, including staff nurses, advanced practice nurses, case managers, educators, researchers, and consultants, and other healthcare professionals, benefit from membership. The Society offers useful information and opportunities for nurses at all levels, in all practice settings, and in all subspecialties.