In Pursuit of the Question Mark, at the Mitchell Library in Glasgow, will survey the life and work of Wyllie, who died in May, and will feature works never seen before, as well as previously shown works rescued from obscurity.
The curator of the show, Mr Wyllie's elder daughter Louise, is looking through her father's voluminous archives of work, papers and sculptures for the show and has rediscovered a number of old works as well as finding new art.
Among the 300 artworks in the exhibition will be hand-drawn Christmas cards the artists sent from the HMS Argonaut in 1944, and work from the 1960s when Wyllie worked with Ron McKinven, the footballer-turned architect and interior designer.
The exhibition will open at the Mitchell Library on November 3 and run until February 2, and will feature ashes from the Straw Locomotive, which was burned after its display.
Wyllie, who died in hospital in Inverclyde at the age of 90, described himself as a "scul?tor" because he claimed the question mark was too important to be left to the end.
In the show, his family are revealing work never seen in public, including his earliest oil painting called The Rescue dating back to 1951.
Some of the artist's earliest sculptural work has also been tracked down, including a Bumper Dolphin, made from old car bumpers, dating to the 1960s, which was at Dunoon's Dolphin Bar for many years.
There is also a peacock made from washers and scrap metal along with other early pieces of work from the 1960s, in Motherwell's United Services Club.
Ms Wyllie said: "The much-loved dolphin sculpture was a focal point in the town centre Dolphin Bar for many years.
"It guarded handbags, was a static dancing partner and propped up weary revellers who little realised it was the early work of one of Scotland's best-known artists."
All the major themes in Wyllie's work will be represented in the exhibition – boats, birds, engines, spires and on to space, which he focused on in latter years.
The show will also feature material that shows how Wyllie created his most famous but ephemeral works, the Straw Locomotive and the Paper Boat.
A cardboard box will contain the ashes of the Straw Locomotive, which burned in a Viking-style "funeral" at Springburn after being taken down from the Finnieston Crane. There will also be illustrated story books which Wyllie produced.
Ms Wyllie added: "My father always said he preferred miscalculations as they offered more promising results. This exhibition is a tribute to this guerrilla-style approach to making art and involving as many people as he could in the process.
"He knew about the exhibition before he died and was happy his legacy would be celebrated. It mattered to him that ordinary people engaged in his art because it asked big questions."
She added: "At a recent event to celebrate his work in the Scottish Parliament, leading Scottish contemporary artist Roderick Buchanan talked about his influence. Roddy said 'George taught us to think big' and it this spirit we are celebrating in the exhibition."
As part of the Big Little Paper Boat schools' project, which will see schools studying aspects of Wyllie's work, the exhibition will also feature a life-size boat shed housing paper boats made by Scottish school pupils.
The boats will be taken to the Riverside Museum on New Year's eve, the date on which Wyllie would have turned 91, and launched in the River Clyde. The exhibition is part of a year-long festival being presented by The Friends of George Wyllie under the banner TheWhysman Festival.