The space will cover 10,000 square metres of the Nedlands foreshore, along the Swan River.
The announcement comes after five years of planning and fundraising by Perth’s four major rotary clubs and other sponsors.
The project was inspired by research about the mental, physical and social benefits of exercise.
Subiaco Rotary Club fundraising committee member Cheryl Jennings said the play space was designed to be used by people of all ages and abilities.
“It’s been proven that play is important for the development of people’s abilities and mental acuity, and I would imagine research would probably show it would assist in an older person’s abilities as well,” she said.
“I have experience of family members with dementia and once they get outside and start to enjoy it, it brings back memories.”
West Perth Rotary Club ex-district governor Angus Buchanan said he hoped construction would start in November.
“Up to this point it has been a big vision and a big dream and now we’re at the point where this time next year it will be reality,” he said.
Mr Buchanan said $1.5 million had already been raised and it was hoped that another $2.5 million could be raised by the end of the year through community fundraising.
The playground will also include a sensory garden, specially designed swing and balancing equipment.
It was designed by an international architect, who worked with groups that develop standards for inclusive playgrounds.