Williams was a wild card in the $2 million tournament, which she has now won three times, and scored her first title-match win since 2012 in Luxembourg.
Williams' stellar career had been derailed by health issues in 2011 and 2012, but she was in fine form Saturday while taking on Cornet, who had defeated Serena Williams in the semifinals.
Venus was down 2-1 early on but took control and did not lose a game the rest of the way. "Everything was falling together," said Williams. "That's all I can say.
Cornet also appeared to be on the ascent in Dubai. She reversed a 28-match losing streak against Top 10 players by beating Simona Halep in the first round and then upsetting Serena Williams.