Abstract: This invention relates to catalyst supports made by spray drying an emulsion polymerized latex and the novel supported catalysts utilizing these supports. This invention further relates to a method for forming supported catalysts by spray drying a latex of microparticles containing catalyst or catalyst components. The polymizerable monomers used in the latex are e.g. styrenes, vinyl benzenes, vinyl cyclohexane and vinyl cyclohexene and can form homo- or copolymers which may be crosslinked. The catalysts supported include metallocenes as well as Ziegler-Natta catalysts. Processes of polymerizing olefins using such catalysts are also described.