Out of passion to care for the physical, emotional and social well-being of the community, the St. Andrew's Medical Mission was founded in 1913 by Dr. Charlotte Ferguson-Davie, the wife of the first Anglican Bishop of Singapore who was also a medical doctor herself. Seeing the plight of the local women and children of that time and the lack of medical services for them, Dr. Ferguson-Davie set up a dispensary along Bencoolen Street for the destitute women and children. The Medical Mission continued to meet the locals' needs and thus led to the opening of more dispensaries and eventually, St. Andrew's Mission Hospital in 1923 and St. Andrew's Orthopaedic Hospital in 1939.

Working closely with the Government, SAMH constantly developed its services to meet the relevant needs of our local community at all times. Today, SAMH has under its operation: St. Andrew's Autism Centre, St. Andrew's Community Hospital, St. Andrew's Nursing Home, St. Andrew's Senior Care, St. Andrew's Migrant Worker Medical Centre, St. Andrew's Mission School and St. Andrew's Mission Hospital Clinic.

- St. Andrew's Autism Centre: Provides special needs services to children and adults with autism.

- St. Andrew's Community Hospital: Provides intermediate rehabilitative and medical care for the community.

- St. Andrew's Nursing Home (Buangkok, Henderson, Queenstown, Taman Jurong) and St. John's - St. Margaret's Nursing Home: Provide long-term nursing and rehabilitative care for residents, including persons with dementia and mental health conditions.

- St. Andrew's Senior Care (Henderson, Queenstown, Tampines Central, JOY Connect): Provide community rehabilitation, day care, dementia day care, centre-based nursing, integrated homecare services (medical, nursing, therapy) and community case management services.

- St. Andrew's Migrant Worker Medical Centre: Provides dental consultation and treatment, mental well-being counselling for migrant workers as well as treats acute, sub-acute and chronic medical conditions.

- St. Andrew's Mission School: Caters to children and youths on the autism spectrum who are able to access the national curriculum at the primary and secondary levels. Provides a holistic education that is focused on the mainstream academic curriculum, and enhanced by life and vocational skills training.

- St. Andrew's Mission Hospital Clinic: Located within St. Andrew's Community Hospital, the clinic provides patient education and general practitioner services such as non-emergency general medical consultation, wound dressing, health screening, vaccinations.