Red Crown is producing the indie film, which will start production in September in Florida.
Cathy Konrad will produce via her Tree Line Films banner along with Jami Gertz and her Lime Orchard Production banner. Red Crown principals Daniela Taplin Lundberg, Riva Marker and Daniel Crown are also producing.
"Three Little Words" will be fully financed by Dover Shores Capital, a New York-based private equity company.
Lewis Colick and Michael Petroni wrote the script based on the the 2008 New York Times bestseller “Three Little Words: A Memoir” by Ashley Rhodes-Courter.
Story follows a young Florida girl who gets lost in the child welfare system for five years until she's discovered by an unpaid volunteer (Witherspoon) who must convince the girl's biological mother to release her parental rights.
Witherspoon currently stars in "Mud" and is in negotiations to join Keanu Reeves in "Passengers."