His compatriot Joe Kovacs won his third straight silver and Jamaica's Rajindra Campbell took bronze.
World record holder Crouser battled with a nerve issue in his elbow this year but had no issues at the Stade de France as he produced his best throw of the season on his third attempt and clapped with satisfaction.
"I feel so lucky to be out there competing. This year hasn't been easy," said Crouser, who also claimed gold at the Rio and Tokyo Games.
"Took a lot to get back to where I had been in the past. It’s made it all the more special to be out there tonight. There were a lot of times I thought I might not be."
The win underlined the United States' total dominance of the event as they have now won 20 men's Olympic shot put gold medals. The next closest country is Poland with three.
Twice world champion Crouser clapped his hands and cheered as he posted 22.64 on his opening throw which would have been good enough to get him to the top of the podium.
He urged on the crowd before making his second attempt and pumped his fist after throwing 22.69 and the fans erupted as he improved that mark with his third throw.
Rain began to spit down midway through the competition and several competitors slipped, including Crouser, who had fouls on his next two attempts and did not make a sixth throw having locked up the gold.
Crouser, who has said he believes he can improve his own world record of 23.56, raised his arms aloft and grinned widely as the crowd cheered his latest achievement.
Jamaican Campbell had been on few people's radars heading into Saturday's action but got the crowd's attention with a tremendous 22.15 throw on his second attempt.
Kovacs was fourth in the standings when he got onto the podium in dramatic fashion, heaving the shot 22.15 on his final attempt in the rain to equal Campbell's best mark.
He took silver over the Jamaican on the strength of his second-best throw.
"The rain came in, and it was tough conditions towards the end. It helped to be leading, but the throw of the day goes to (Kovacs)," said the modest Crouser.
"Was the most impressive throw I’ve ever seen him take."
