After graduating with a Bachelor of Arts degree from Laval University in 1902, he moved to the village of Paquetville, Gloucester County, in northeastern New Brunswick.

Active in community affairs, in 1909 he was elected to the Municipal Council for Gloucester County, a position he held until 1911 and then again in 1922-23.

From 1910 to 1918, Doucet worked as a surveyor in forestry for the Interior Ministry of the Government of Canada in Ottawa, Ontario.

In 1923, André Doucet successfully ran as the Liberal party's candidate in a Gloucester by-election for a seat in the 35th New Brunswick Legislative Assembly.

Following his party winning power in the 1939 election, the new Liberal Premier, John McNair appointed Doucet the Minister responsible for NB Power and then on March 13, 1940 to Minister of Health and Community Services, a position he would hold until September 27, 1944 when he was appointed to the newly created Ministry of Industry and Reconstruction.