The Spaniard took little time in asserting his authority, taking the first set in just over half an hour. Raonic had got one break back as Nadal served for the match, but that only delayed the inevitable.
It looked as if the Canadian was struggling to cope with the occasion in Montreal as he failed to find any rhythm.
Once again, the Nadal broke at the first time of asking in the second set, before battling back from 0-40 to establish a 3-1 lead. He then went on to seal victory for the third time in Canada in 68 minutes.
The title is his eighth this year, and 25th overall in the Masters Series.