EXA Atlantic (formerly GTT Atlantic, Hibernia Atlantic) is a 12,200 km private transatlantic submarine cable system in the North Atlantic Ocean, connecting Canada, the United States, Ireland and the United Kingdom. The EXA Altlantic consists of EXA South and EXA North cables.

Hibernia Atlantic Submarine Cable System was ready for service on April 8, 2001, with a design capacity of 10.16 Tbps.

In January 2017, GTT completed the acquisition of Hibernia Networks for $USD607 million (initial price was $590 million) , which includes Hibernia Express, Hibernia Atlantic and other assets.

In September 2021, I Squared Capital, an infrastructure private equity firm, acquired GTT's Communications’ infrastructure division for an initial $1.74bn in cash, and renamed the newly independent operating company EXA Infrastructure. The GTT Atlantic and GTT Express, as part of assets covered by the acquisition, are now renamed as EXA Atlantic (EXA South and EXA North) and EXA Express.