The move comes as the GTCS prepares to become the world's first independent regulator of teaching and assumes its new responsibilities in April 2012.
Osler has been appointed as head of corporate comms and information services, a role created following a wider restructure at the regulator.
He will be responsible for communicating the impending changes to teachers, stakeholders, parents and pupils.
He will manage a nine-strong team, with responsibility for internal and external comms, web services, events and customer services. He reports directly to the GTCS CEO Anthony Finn.