On 12 January 2012, Rämö was traded (along with Michael Cammalleri and a fifth-round pick in the 2012 NHL Entry Draft) to the Calgary Flames in exchange for Rene Bourque, Patrick Holland and a second-round pick in the 2013 NHL Entry Draft. On 5 July 2013, Rämö signed a two-year, $5.8 million contract with Calgary, paving the way for his return to the NHL. Ahead of the 2013–14 season, during the pre-season, he won the job to replace the retired Miikka Kiprusoff as Calgary's starting goaltender over Joey MacDonald and Reto Berra.