Press Release

GTT to Present at the Jefferies 2016 Technology Conference

McLean, VA, April 28, 2016

GTT Communications, Inc. (“GTT”) (NYSE: GTT), the leading global cloud networking provider to multinational clients, will present at the Jefferies 2016 Technology Conference in Miami, Florida. Mike Sicoli, GTT CFO, is presenting on Thursday, May 12, at 1:30 p.m. ET, and meeting with investors that day. A webcast of the session and a copy of the company’s latest investor presentation can be found on the company’s website. About GTT GTT’s global Tier 1 IP network enables clients to connect to any location in the world and with any application in the cloud. Our cloud networking services provide a better way for multinational clients to reach the cloud. Clients trust us to deliver secure solutions with simplicity, speed and agility. For more information, visit www.www.gtt.net

GTT Investor Relations: Jody Burfening/Carolyn Capaccio, LHA +1 212 838 3777 [email protected]

GTT Media Inquiries: Ann Rote +1 703 677 9941 [email protected]