Buyer Found for Diane Keaton's $23 Million Mansion

Diane Keaton's massive mansion has found a new owner ... for a casual $23 million ... TMZ has learned.

Sources familiar with the situation tell TMZ ... the sprawling 9,219-square-foot property went under contract on Friday -- meaning they've found a buyer and accepted an offer ... but there are still some conditions that need to be met before the sale can go through.

The estate boasts 5 bedrooms and 8 bathrooms, as well as a gorgeous kitchen with a custom-built island, chicken-wire cabinetry, and pendant lights repurposed from a former chicken coop.

DK's vision for the home was inspired by "The Three Little Pigs" ... which you can see in the 75,000 hand-selected, Chicago-sourced bricks that form the home's foundation.

She first listed the posh pad before she died ... initially asking for $28.9 Mil. After a couple months, they lowered the price of the listing -- which is represented by luxury real estate broker Josh Flagg -- but removed it altogether weeks before Diane passed away.

Since then, they've relisted, removed, and slashed the price further ... but it sounds like they've finally found someone to scoop up the estate.