Emery stopped all 16 shots he faced in the victory, which got the Blackhawks back on track after two consecutive losses.
Leddy got the Hawks on the board at 7:09 of the first period. Seabrook put the game away late in the second period.
Chicago outshot the Flames 35-16 but both teams were 0-4 on the power play.
Miikka Kiprusoff made 33 saves, but Calgary lost a team-record 10th consecutive road game.
Notable deaths of 2014 [PHOTOS]