Hargreaves will focus on new and existing clients, specialising in the conference suites, cinemas and meetings with fewer than 300 delegates.
Barbican head of corporate sales Anthony Hyde said: "This appointment shows that despite the recession, the Barbican is continuing to invest in its staff in order to strengthen our position as Europe's leading combined conference and arts centre. We are looking at the future positively and Oliver Hargreaves will bring additional energy to the team."
He joins the Barbican with a degree in events management with marketing management from the University of Gloucestershire, and has also spent a year at the Cotswold Conference Centre.
Hargreaves said: "I am looking forward to working with such an experienced team and the challenges and opportunities that lie ahead."