This document discusses electrophilic aromatic substitution reactions of phenols. It describes how the hydroxyl group strongly activates the aromatic ring towards these substitutions. It then lists and provides brief examples of common electrophilic aromatic substitution reactions that can occur with phenols, including halogenation, nitration, sulphonation, Friedel-Crafts alkylation, and Friedel-Crafts acylation. Reaction conditions and products are noted for some of these substitutions.