Spieth's heroics beat out Daniel Berger of the United States.
Each of the past seven majors has been won by a different player.
The Northern Irishman had argued against the grass being cut back before the start of the tournament.
The 28-year-old has never won a major tournament.
Erin Hills is "like a links golf course on steroids," Spain's Jon Rahm has said.
The U.S. Open begins on Thursday at Erin Hills in Wisconsin.
The winner of the tournament will receive a cheque for $2.16 million.
Spieth is the youngest golfer to win both the U.S. Open and Masters in the same year.