The Americans hardly made a mistake in the finals, with Biles helping them to a score of 172.330 — 5.801 points more than second-placed Russia.
Italy (164.796) took third spot for its first world team medal since 1950, while China slipped off the podium for the first time since 2003.
Biles secured her 21st world medal, overtaking Russia’s Svetlana Khorkina for the women’s record.
Only Vitaly Scherbo of Belarus has won more world medals with 23, which Biles could surpass by the end of the individual events this week.
“I guess it’s kind of crazy,” said Biles, who collected a record-extending 15th gold medal at the worlds.
“I feel like I haven’t gotten the chance to process it yet.
“But I think we’ll do some celebrating tonight, for all of it. For the team, for the medal count, for the fifth year in a row.”
Biles is likely to break records almost every time she is in action this week but the 22-year-old conceded she still feels the pressure of delivering results on the world stage.
“Sometimes, I wish I would quit because the other day we walked out there, and I was like, ‘I literally hate this feeling. I don’t know why I keep forcing myself to do it,’” she told the Olympic Channel.
“But you know, we love the thrill of it. It reminds me to never give up because, one day, I won’t have the opportunity to get that feeling.”
The Americans wasted no time on their path to glory, with Grace McCallum, Jade Carey and Biles landing three solid vaults in a row to give them an early lead.
Sunisa Lee faltered on the beam, just as she did in Saturday’s qualifying round, but Biles continued to showcase clinical execution to post the highest scores on three out of four apparatus.
By the time Biles approached the floor exercises, she needed only a 9.533 to clinch gold.
She wrapped up the contest in style with a triple-twisting double back flip — now known as the Biles II — to finish with 15.333.
It was a much cleaner effort from Biles, who stepped out of bounds to earn a 0.2 penalty in qualifying.
“It was a little bit nerve wracking, but it was kinda fun,” Biles added. “I stayed in bounds. So I think that was the highlight of the night.”
Italy huffed and puffed into the finals by grabbing the eighth and final qualifying spot but going into the final rotation they were in second place, trailing the U.S. by 2.434.
Reigning Youth Olympic Games champion Giorgio Villa led the team and posted consistent scores across all apparatus to ensure they took third spot, finishing 0.566 clear of fourth-placed China.
Reporting by Hardik Vyas in Bengaluru; Editing by Christian Radnedge