Saint-Thomas-Didyme is a municipality in Maria-Chapdelaine Regional County Municipality in the Saguenay–Lac-Saint-Jean region of Quebec, Canada. It had a population of 703 in the Canada 2021 Census.

Demographics

Population trend:

• Population in 2021: 703 (2016 to 2021 population change: 4%)
• Population in 2016: 676
• Population in 2011: 677
• Population in 2006: 708
• Population in 2001: 797
• Population in 1996: 855
• Population in 1991: 944

Private dwellings occupied by usual residents: 364 (total dwellings: 518)

Mother tongue:

• English as first language: 0%
• French as first language: 96.5%
• English and French as first language: 0%
• Other as first language: 3.5%