Jere Hausfater's Essential Entertainment is handing worldwide sales at EFM.
The project is based on a true story told by George Hamilton to Merv Griffin about his early life on the road with his flamboyant mother and brother.
Zellweger will play the glamorous Anne Deveraux who drives down the US East Coast in search of a wealthy man to fund a new life for her and her sons.
Aaron Ryder of Raygun and Ara Katz and Art Spigel of Artfire Films will produce and Artfire is financing.
Merv Griffin Entertainment's Ron Ward and Rob Pritchard are serving as executive producers with Artfire's Dan Fireman, George Hamilton of George Hamilton Productions and Robert Kosberg.
My One And Only will be dedicated to the memory of Merv Griffin, who shepherded the project from idea to final script.