The multifaceted implementation of silanols in organic synthesis is reviewed from the standpoint of developments in transition metal-catalyzed reactions. The major properties of silanols are summarized according to the research fields that have utilized these intriguing species: silanols as nucleophiles to serve as bulky surrogates for water; silanols as temporary ligands to control regioselectivity of metal-catalyzed reactions; silanols as coupling partners for transferring functional groups. These topics are summarized to provide opportunities for future developments in the chemistry of silanols.