Brock, currently international editor of the Times and former president of the World Editors' Forum (2004-8), started his career at the Yorkshire Evening Press as a graduate trainee and reporter, before becoming home affairs reporter for The Observer in 1976.
He joined the Times in 1981, where he held various roles, including opinion editor, foreign editor, managing editor and Saturday editor.
"With the changes and challenges of digital publishing, this is an important moment for the training of the next generation of journalists. It's a great honour to lead best journalism school in the country," Brock said, in a statement from City University.
President and vice-chancellor of City University London, Professor Malcolm Gillies, said: "George Brock comes to the university with three decades of work as a practical reporter, editor and manager. We look forward to seeing him inject a heightened spirit of internationalism into the Journalism School."
Earlier in the year City University moved into its £12 million re-developed premises, with new digital facilities, including two sound-proof audio rooms for radio and podcast recording, a digital editing suite and a broadcast studio.
The department includes the UK's first graduate school of journalism; with 4,000 alumni and 272 current postgraduate journalism students it is 'probably the world's largest,' Monck told Journalism.co.uk in Februrary.
Monck, who will maintain links with the university, wrote about his years at City in a blog post today, published on the Journalism.co.uk Editors' Blog.