South Eastern Sydney and Illawarra Area Health Service (SESIAHS) was formed in 2005 from the amalgamation of the Illawarra Area Health Service and South Eastern Sydney Area Health Service. It was disbanded on 1 January 2011 as part of the National Health Reform and creation of Local Hospital Networks. It was a statutory body of the New South Wales Government, operating under the NSW Department of Health, charged with the provision of public health services in eastern and southern Sydney, and regions to the south of Sydney. The area's Area Health Advisory Council was headed by .