Ramo, who turned 27 years old on Monday, has not played in the NHL since 2008-09 when he split time between the Tampa Bay Lightning and Norfolk Admirals in the American Hockey League.
He has spent the past four seasons with Omsk in the Kontinental Hockey League. Ramo has had a goals-against average or 2.00 or lower and a save percentage of .925 or high in each of the past three seasons. Ramo will have a chance to replace Miikka Kiprusoff, who retired last month, as the starting goalie in Calgary.
In 48 career NHL games, Ramo is 11-21-10 with a 3.21 GAA and .895 save percentage, all with the Lightning.
The Flames also announced two other signings Friday. Center Corban Knight, whom they traded a fourth-round pick in the 2013 NHL Draft to acquire, signed a two-year, entry-level contract and center Greg Nemisz, the team's first-round pick in 2008 who has one assist in 15 career NHL games, inked a one-year, two-way deal.