He represented the city of Montreal in the Legislative Assembly of the Province of Canada from 1843 to 1844 and represented Chambly from 1848 to 1849.
In 1849, he resigned to become medical superintendent at the Montreal prison; he served in that post until his death.
Beaubien also taught at the Montreal School of Medicine and Surgery, becoming president of the school in the 1860s and served as public health officer for the city of Montreal.
He died in Outremont in 1881.
His son Louis served in the House of Commons of Canada and the Legislative Assembly of Quebec.
Beaubien Street and Beaubien Metro Station are named after him.