The top seeds backed up their French Open win eight days ago on clay in Paris with a grass court victory and Wimbledon just around the corner.
"It's unbelievable beating these guys two weeks in a row in finals," said Nestor. "They are probably our toughest opponents and the best team in the world over the long term.
"Max was serving really well, I think we've made a good switch over to grass. Now we have to stay sharp for Wimbledon."
The 39-year-old from Toronto has now won the Queen's Club doubles title four times. Nestor and Mirnyi will be top doubles seeds when Wimbledon begins on June 25.
Nestor and Mirnyi now own four titles in 2012 — Brisbane, Memphis, the French Open and Queen's. Nestor also won the Queen's with Mark Knowles in 2003 and 2007, and with Nenad Zimonjic four years ago.
Nestor and Mirnyi defeated the Bryans in just 51 minutes thanks in large part to seven aces.
They won the first set after a Bryan double-fault set up three set points. Mirnyi then began the second set with a love game and followed that up with one more break of the Americans.