Sol–gel materials have a number of properties that make them ideal for supporting heterogeneous catalysis. This chapter focuses on the use of organic molecules to affect the catalytic properties of sol-gel materials (e.g., tailoring-specific porosity); on the use of organically modified precursors; on the entrapment of organometallic catalysts; and briefly on the entrapment of enzymes and catalytic antibodies. All of these utilize the special property of sol-gel materials, namely, that they are prepared at convenient temperatures. The chapter brings an example of how the stereochemistry of a catalytic reaction was controlled by sol-gel imprinting with the desired stereoisomer. It mentions the enantioselective reduction of itaconic acid by a number of entrapped chiral organometallic catalysts. The chapter also discusses industrial success stories of sol–gel-based catalysis.