The big-hitting third seed used his thumping serve to ace his way to a well-deserved win against his Czech opponent, who was looking to win his first title since Stockholm last October.
Raonic, who beat defending champion Richard Gasquet in the semi-finals on Saturday, fired down 18 aces - his last to set up a pair of match points.
After winning the first set in a tight and tense tiebreaker, the 22-year-old tightened his grip in the second with an important early break with his only opportunity of the match, before serving out the match.
The trophy, his second of the season, will help the 11th-ranked Canadian as he bids for a place in the eight-man season-ending ATP World Tour finals in November in London.
Berdych remains the only member of the ranking top 10 without a title in 2013.
"I think I'm playing great tennis, I'm serving really well, I'm doing a lot of good things,'' said Raonic.
"If I keep that up I think I'll have opportunities and will put myself in a good position, no matter who I play.''
Reflecting on his chances of reaching the London showpiece, he added on atpworldtour.com: "It would mean a lot, it was a goal.''
Elsewhere at the event, Britain's Jamie Murray teamed up with Australia's John Peers to win Sunday's men's doubles final.
The third seeds needed just 71 minutes to get the better of fourth-seeded duo Tomasz Bednarek and Johan Brunstrom in a 6-3 3-6 10-6 win.
The victory was the third for Murray and Peers since they paired up at the start of this year, following on from titles in Houston and Gstaad.