Williams, who finished runner-up last year, needed just 62 minutes to earn her 62nd career singles crown.
"It was such a great week," Williams said. "She was playing so hard, hitting so many winners."
This also marked Williams' second title in the month of August as she looks to be in fine form heading into the season's final major, the US Open which begins August 25 in New York.
Williams, who turns 33 next month, won nine of the last ten games to cruise to the victory over the ninth seeded Serb.
Williams hammered 12 aces and 26 winners in her victory.
"I just kind of close my eyes and serve," Williams said. "When you think about it too much you get kind of crazy."
She now has five wins in 2014 to go with victories in Brisbane, Miami, Rome and Stanford.
Ivanovic was playing in her first final on North American soil since 2009 in Indian Wells.