In analogy to ferromagnets, ferroelectric materials develop remnant macroscopic electric fields that can be switched by applying an external field. The bulk electronic polarization is stabilized by compensating charges at the surface that can be supplied by adsorption or electronic and structural reconstructions. Because opposite compensating charges are required on oppositely poled surfaces, ferroelectric materials offer unique opportunities to create surfaces with switchable chemical properties. Further, thin ferroelectric films would be expected to switch their polarization in the presence of molecules that preferentially adsorb on one of the polar surfaces, suggesting a new avenue for chemical sensing. It will be shown that the adsorption of polar molecules such as alcohols and carboxylic acids depends on the ferroelectric polarization direction, with stronger adsorption on positively poled LiNbO3. The differences in adsorption strengths are comparable to the energy required to switch 20 nm thick ferroelectric films, thus ferroelectric chemical sensing is feasible. This possibility is further explored through in situ measurements of changes in polarization of thin epitaxial titanate ferroelectric films in response to oxidizing and reducing environments. A limitation to switchable chemistry, however, is the low reactivity of typical ferroelectric oxides. Efforts to increase the reactivity through deposition of catalytic metals fail because the metals form three-dimensional clusters whose surfaces are too far from the ferroelectric substrate to be affected. Results of a combined experimental/theoretical approach to identifying catalytic oxides that form stable, atomically thin layers whose reactivity is influenced by the polarization direction of the ferroelectric will be presented. Specific examples include Cr2O3/LiNbO3 and perovskite layers on ferroelectric titanates.