The couple took their boy, Noah, out for a celebratory birthday dinner where he was treated to chocolate cake.
Michael wrote on his facebook a sweet post: "Celebrating a very big birthday with my two most favourite people in the world!! Happy 1st Birthday kiddo! #family #celebrate #birthday boy #the best Luisana Lopilato
Luisana's friend Diego Topa also shared a cute picture with the birthday boy.
The happy day ended with Luisana and Noah letting some balloons to the sky and Luisana posted a video of the moment on facebook and instagram.
In the snap, Luisana is wearing a white lace bra and open denim shirt, meaning her bare baby bump is on show, and she is cuddling in to the Canadian crooner.
Commenting, she wrote: "Thank you @michaelbuble for making me the happiest woman in the world!!! #happybdayson #proudmom #canadianargentinianbaby."
The second picture she shared was one of her first birthday in the arms of her parents Betty and Eduardo.
"Today Noah turns 1 years old. Seeing this picture of my first birthday I realize how alike we are." she commented.