He was born in Hinton St. George in England in 1798, the son of John Tett who manufactured cloth for ships' sails, and came to Perth, Upper Canada in 1820, later moving to Newboro.
Around 1830, he set up a sawmill north of Kingston at Bedford Mills, anticipating the completion of the Rideau Canal.
In partnership with the Chaffey family and others, he established a booming timber business in the area.
Tett ran unsuccessfully in Leeds for a seat in the legislative assembly of Upper Canada in 1838.
His daughter Elizabeth married doctor Robert Henry Preston, who later represented South Leeds in the provincial assembly.