The alkylation of phenol with methanol and dimethyl carbonate on the micro- and mesoporous materials MFI, BEA, and MCM-41 in the H+ form and modified by Cs+ ions and cesium hydroxide (to obtain acidic and basic catalysts) was studied. The activity and selectivity of phenol alkylation were shown to depend on the type of active sites and structural characteristics of the catalyst, as well as on the nature of the alkylating agent. The base zeolites possess the highest selectivity with respect to anisole, whereas the highest selectivity for cresols and xylenols is displayed by acidic catalysts and zeolites with strong acid sites and pores with diameters greater than 7 angstrom, respectively. Dimethyl carbonate is a more effective O-alkylating agent than methanol.