A catalyst system comprising a combination of: 1) an activator; 2) one or more metallocene catalyst compounds; 3) a support comprising an organosilica material, which may be a mesoporous organosilica material. The organosilica material may be a polymer of at least one monomer of Formula [Z1OZ2SiCH2]3 (I), where Z1 represents a hydrogen atom, a C1-C4 alkyl group, or a bond to a silicon atom of another monomer and Z2 represents a hydroxyl group, a C1-C4 alkoxy group, a C1-C6 alkyl group, or an oxygen atom bonded to a silicon atom of another monomer. This invention further relates to processes to polymerize olefins comprising contacting one or more olefins with the above catalyst system.