The “House of Cards” star had asked that his lawyers represent him at the hearing, but Judge Thomas Barrett declined, forcing Spacey to appear before him at 11:00 am (1600 GMT).
The formal charges come more than 13 months after the complaint was filed, and is part of the latest chapter in the #MeToo movement after the sentencing of actor Bill Cosby and the indictment against Hollywood producer Harvey Weinstein.
The case marks the first time Spacey has faced charges, although there are dozens of claims against him.
The actor faces five years in prison if charged for repeatedly reaching down into the pants of a man identified as William Little, who was 18 at the time of the alleged assault in July 2016 at a Nantucket restaurant.
The young man had been working as a bus boy for the summer at the restaurant.
He had remained in the bar after his shift had finished to see Spacey, of whom he was a fan.
After meeting the actor and telling him he was 23 years old — the legal drinking age is 21 in Massachusetts — he said he started drinking first beer and then whiskey with Spacey at his urging.
Spacey then allegedly invited him back to his place, along with some other friends. The young man declined, suspecting the actor was trying to seduce him. But he stayed in the bar in the hopes of getting a picture with Spacey.
It was then Spacey began sexually molesting the young man, according to court filings.
The two-time Oscar winner — for his supporting role in “Usual Suspects” in 1996 and his lead role in “American Beauty” in 2000 — told the judge in a letter that he intends to plead not guilty.
– ‘Without evidence’ –
Spacey, who was forced out of public life by accusations of sexual misconduct in 2017, posted a video online in December of himself speaking about allegations of sexual abuse in the character of Frank Underwood, the scheming politician he played in “House of Cards” before the show dropped him.
The message has several levels of interpretation, evoking both the destiny of Underwood, the lead character written off the show, and the claims against Spacey.
“You wouldn’t believe the worst without evidence, would you? You wouldn’t rush to judgments without facts, would you? Did you? No, not you. You’re smarter than that,” Spacey said in the video.
“Of course, some believed everything and have been just waiting with baited breath to hear me confess it all. They’re just dying to have me declare that everything said is true and that I got what I deserved.
“Only you and I both know it’s never that simple, not in politics and not in life.”
Spacey was considered one of the finest actors of his generation, but his career nosedived following allegations of sexual misconduct by more than a dozen men in the United States and Britain.
In addition to the Nantucket case, two other investigations are underway in Los Angeles and London, where Spacey served as artistic director of the prestigious Old Vic theater from 2004 to 2015.
Mexican actor Roberto Cavazos, who performed in several Old Vic productions, said “it seems that it only took a male under 30 to make Mr Spacey feel free to touch us.”
The first public report of alleged abuse by him came from actor Anthony Rapp, who claimed that Spacey sexually abused him when Rapp was 14, in 1986.
Spacey has not appeared on the screen or on stage since Rapp came forward.
Director Ridley Scott even removed Spacey from his film “All the Money in the World” (2017) by shooting all scenes in which the actor appeared again with another star, Christopher Plummer.