The American, possessor of the fastest serve in tennis and conqueror of Andre Agassi in the semi-final, took just 59 minutes to wipe the Frenchman off the court.
"They're not joking around here," Roddick smiled as he was handed the enormous silver cup. "That thing's bigger than I was when I was 12-years-old.
"It is pretty humbling to be in the same category as some of the names on that trophy... anyone who's anyone has won here. I couldn't be happier right now."
Roddick joins an illustrious list of former champions of the Queen's Club event including John McEnroe, Jimmy Connors, Boris Becker and Pete Sampras.
He pocketed 94,700 euros ($111,300) for the one-sided victory but more importantly it will serve as a major confidence boost eight days ahead of Wimbledon.
"It is great," he said. "I will relax now and then come back in a week's time and try to do it all over again at Wimbledon."
A single break in the first set was enough for the American to clinch it on a scorching day.
LUCKY NETCORD
The third seed broke for 4-2 in the opening set when, having clawed his way back from love-40, Grosjean double-faulted.
A second break for 2-1 in the second put Roddick firmly on the path to victory, one he completed when he broke again for 6-3, winning match point on a lucky netcord.
"Everything went my way today," Roddick said. "Even that match point... it was laughable."
While the American failed to repeat his feat of Saturday when he crunched down a 149 miles (239.8 km) per hour serve to equal the fastest ever, his deliveries were still too hot to handle for the Frenchman.
Parading the baseline in a deep red shirt, Grosjean was never given the time he needed to set up his shots and looked only a patch of the player who destroyed Tim Henman in the semi-finals.
"Well, he had a great week here," Grosjean said of his opponent. "He served really big so it was tough to return.
"Still, I am pleased with my week. I beat Lleyton Hewitt and Henman... I am happy."
Roddick said he had enjoyed his week in the British sun and would definitely return.
"Hey, how 'bout this English weather," he said. "It's great... I've had a great week here.
"I will certainly be back next year."
The title came in his first week under the guidance of Brad Gilbert, former coach of Agassi.
"We have been working on a few things," Roddick said. "Brad told me, if I am going to miss I might as well miss really going for it, not making some stupid error.
"It seems to be working."
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