Functionalized catalyst supports useful in formation of supported catalyst systems for the polymerization of olefins are disclosed. Methods for preparing functionalized catalyst supports and supported catalyst compositions therefrom as well as polymerization processes utilizing such supported catalysts are also disclosed. The functionalized catalyst support comprises a particulated support material having chemically bonded thereto a plurality of non-ionic, Lewis acid, aluminum-containing groups containing at least one fluoro-substituted hydrocarbyl ligand containing from 1 to 20 carbons bonded to the aluminum, said support being capable of activating a Group 3-10 metal complex for the addition polymerization of one or more addition polymerizable monomers.