Blake turned heads in a show-stopping strapless monochrome gown which she accessorised with a glittering diamond necklace, earrings and a cuff bracelet.
Blake Lively and Ryan Reynolds
The 26-year-old Californian opted for a simple but elegant beauty look, adding a pop of colour with scarlet lipstick and nail polish and sweeping her blonde locks into a low bun.
Ryan, 37, echoed his wife's black and white outfit in a smart tuxedo, complete with a white bow tie.
The duo were out to support Vancouver-born Ryan's latest silver screen venture, The Captive, in which he plays a landscape gardener whose daughter Cassandra was kidnapped while walking through a car-park eight years previously.
The film, which also stars Rosario Dawson, Scott Speedman and Mireille Enos follows Cassandra's parents as they try to work out the mystery of her disappearance and discover if she is still alive.
CLICK ON PHOTOS TO ENLARGE
Blake Lively and Ryan Reynolds tied the knot in 2012
Blake has made several stylish appearance at Cannes this year.