The late reverend Robert Miller, who passed away in 2010, and five residents from around Port Elliot formed a lobby group in 2003, with the hopes that a nursing home would be built in the town.
The group, known as PEACH (Port Elliot Aged Care Housing), included Russell Farr, Helen Jones, Geoff Simpson, Susan Tocher and Alan Oliver.
Reverend Miller's wife, Avis, who is 80 years old, will be the first resident to move into the site.
More than 100 guests yesterday celebrated the culmination of the six year project, with site tours conducted for members of the public.
Richard Hearn, Resthaven chief executive, says the state of the art aged care facility will provide high quality care for up to 94 older people and create about 100 local jobs.
With places already filling rapidly, Mr Hearn claims residents will begin moving into the residential site later this month.
"Four independent retirement living units, located at 54 North Terrace, complete the campus, which takes up an entire block, and is surrounded by new footpaths and landscaping," Mr Hearn says.
Key staff have been appointed, with Strathalbyn's Pamela Alde taking on the role of Manager, Residential Care Services.
"Pamela played a pivotal role in establishing Resthaven’s Mount Gambier site, which opened in July 2011. She is an experienced site manager, and her expertise will be of great benefit to Resthaven Port Elliot," Mr Hearn says.
"I am confident that the range of new services we offer here will provide a much needed service to older people throughout the Fleurieu," he adds.
The Fleurieu Peninsula reportedly had the highest proportion of people aged 65 years and over in the state, last financial year.
Resthaven Port Elliot is located at 3 Frederik Street, Port Elliot.