In a statement Tuesday, the organization said Simmons was suspended due to "conduct detrimental to the team."
"Ben Simmons has been suspended for one game due to conduct detrimental to the team. As a result, Simmons will miss the 76ers' season opener at New Orleans tomorrow night," the statement said.
The suspension means the Sixers All-Star point guard will miss the team's season opener against the Pelicans in New Orleans Wednesday night.
Coach Doc Rivers said he threw Simmons out of practice Tuesday and the suspension came shortly thereafter.
Doc Rivers speaks to media after Ben Simmons suspended
After throwing him out of practice, Rivers was asked if he believes that Simmons really wants to be a part of the team.
"Well, today not - obviously. We told him to go home, but hopefully at some point, yeah I do," he said.
During a news conference, teammate Joel Embiid was asked about Simmons.
"At this point, I don't care about that man, honestly, he does whatever he wants. You know, that's not my job," he said.
"But at the end of the day, our job is not to babysit somebody. We get paid to produce on the court, go out, play hard, win some games ... that's what we get paid for. We don't get paid to come out here and try to babysit somebody. So that's not our job, and I'm sure my teammates feel that way.
Joel Embiid speaks to media after Ben Simmons suspension
Tuesday was the third straight day Simmons had practiced with the team after clearing the NBA's re-entry health and safety protocols Friday. He returned to the team last Monday after a missing the first two weeks of practice as he held out in the hopes of getting his trade request from the offseason fulfilled.
He worked with the second team in practice both Sunday and Monday, and immediately left the court the moment both practices ended.
Sixers fans had plenty to say Tuesday afternoon.
"I'm not surprised...that's his mentality. You can't teach an old dog new tricks," said John Mills.
"It is disheartening to know you've got a team player that's not actually a team player. He seems a bit selfish," added Chavis Nesbitt.
Sixers fans sound off after Doc Rivers suspends Ben Simmons
The 76ers have fined Simmons $1.4 million for his absence from four preseason games ($360,000 each) and levied numerous team fines for missed practices, on-court workouts and meetings, sources told Wojnarowski. Simmons hasn't earned any money since returning to the team on Oct. 11.
By being suspended for Wednesday's game, Simmons will lose roughly another $227,000.
Rivers had previously declined to say when Simmons would return to the court with the team for a game.
ESPN reporting contributed to this story.