The baby-faced 18-year-old from Sheffield, whose younger brother acted as his caddie, sunk a par putt on the 33rd hole to close out a 4&3 victory in the matchplay format tournament held at The Country Club in Brookline, Massachusetts.
"I mean, it's absolutely amazing," said Fitzpatrick, who won the title on the same course where amateur Francis Ouimet claimed his famous US Open victory in a playoff against Harry Vardon and Ted Ray a century ago.
"I can't really describe how I'm feeling at the minute. That's sort of what everyone wants in golf, wants to achieve, and I'm pretty sure Justin Rose said that after his US Open that it's nice to go down in the history books."
Rose became the first Englishman in 43 years to win the US Open when he won his first Major at the Merion Golf Club in June.
The amateur, who grabbed attention last month when he won the silver medal at the British Open as leading amateur, ended England's wait for a victory in the tournament since Harold Hilton lifted the trophy in 1911.
The win earns Fitzpatrick, who is soon to begin a golf scholarship at Northwestern University in Chicago where former world number one and fellow Briton Luke Donald studied, an exemption into the 2014 US Open provided he remains an amateur.
He is also exempt from next year's British Open and is likely to receive an invitation to The US Masters at Augusta.
Fitzpatrick led the 19-year-old Goss by one after the morning round but the Australian tied the match on the opening hole of the second when his opponent missed a seven-foot par putt.
The Englishman, who came into the event as the number two ranked amateur in the world, won the next two holes to take the lead for good.
"I'd probably say this week what's come out most is that my short game has just been really, really top drawer," Fitzpatrick said. "I'd say my weakest part of my game was into the greens.
"What's come out more than anything is I've just putted really well."
- Sports & Recreation
- Merion Golf Club
- Francis Ouimet