Thanksgiving is a human holiday that is normally celebrated in the United States on the last Thursday of November, while in Canada it is celebrated on the same day as Columbus Day in October. The American celebration is usually a commemoration of the Pilgrims landing on Plymouth Rock in 1620 and their surviving the year living in the region, becoming friends with the local Native American tribes in the region. It is celebrated with a feast that includes turkey as the main part of the menu.
While Thanksgiving in itself doesn't appear in either the Smurfs comic books or the Smurfs cartoon show, a Thanksgiving-themed Smurf does appear in the Smurfs Village app.