The head of state wrote on Facebook, Censor.NET reports.
Petro Poroshenko said the document opens a "window of colossal opportunities for Ukrainian business" in trade, state procurement, and e-commerce sectors.
"But it's more important that just a trade deal. It's an eloquent and symbolic gesture of support; it's a great demonstration of a special partnership that is getting stronger between our two states, although remote geographically but close in values, spirit, and aspirations.
"My sincere congratulations to Ukraine and Canada on the new page of our relations," Poroshenko wrote.