He was previously president of the company's Europe, Middle East and Africa business, a position he held since early 2015.
“Landi’s leadership capabilities, proven track record as a sales leader and deep understanding of global organisations make him the right leader for this expanded role," said Polycom chief executive Mary McDowell.
"His extensive knowledge of the Asia Pacific, Europe and Africa regions will enable us to continue to deliver the best experience customers and partners while delivering growth.
Before joining Polycom, Landi worked as Zebra Technologies vice-president of sales, and as vice-president and general manager for the EMEA region at Motorola's enterprise mobility business.
He holds a bachelor's degree in classics from Liceo Classico Luciano Manara, an MA in political science from Sapienza Università di Roma, and an MSc in business and human resources from Alliance Manchester Business School.