Todd and Julie Chrisley, the stars of “Chrisley Knows Best,” a reality TV show in which the couple project themselves as real estate moguls who judge PG-rated family squabbles according to strict standards for comportment, were convicted on Tuesday of conspiring to defraud banks out of $30 million and avoiding years of tax bills, the Department of Justice said.

After a three-week trial in Federal District Court in Atlanta, a jury found the Chrisleys guilty on all counts — jointly, eight counts of financial fraud and two counts of tax evasion, with Ms. Chrisley also being convicted of additional counts of wire fraud and obstruction of justice.

Their accountant, Peter Tarantino, was found guilty of filing false corporate tax returns for the Chrisleys’ company.

“When you lie, cheat and steal, justice is blind as to your fame, your fortune, and your position,” Keri Farley, special agent in charge of the F.B.I. in Atlanta, said in a statement.

The Chrisleys could each be sentenced to as much as 30 years in prison. U.S. Judge Eleanor L. Ross of the Northern District of Georgia set sentencing for Oct. 6.

“Disappointed in the verdict,” Bruce Howard Morris, a lawyer for Todd Chrisley, wrote in an email on behalf of the couple. “An appeal is planned.”

Lawyers for Mr. Tarantino did not immediately reply to requests for comment.

Despite the Chrisleys’ self-presentation as self-made businesspeople, their wealth depended in large part on fraud, according to the indictment against the couple.

They obtained loans, for example, by using a bank statement saying they had $4 million at Merrill Lynch when they did not even have an account with the bank, the indictment said. Mr. Chrisley directed his accountant to perform actions he himself suggested would be “crooked,” and Ms. Chrisley repeatedly used glue and tape to falsify documents, according to the indictment.

The couple used money from loans for “luxury cars, designer clothes, real estate, and travel,” the Department of Justice said, even as they also filed bankruptcy and walked away from more than $20 million in loans. They did not pay the Internal Revenue Service in a timely manner for the 2013 through 2016 tax years, the indictment said.

NBC Universal announced last month that “Chrisley Knows Best” had been renewed for a 10th season. The network also said that “Growing Up Chrisley,” a spinoff starring two Chrisley children, Chase and Savannah, had been renewed for a fourth season, and that a new series, “Love Limo,” a dating show hosted by Todd Chrisley, would begin next year.

The release described “Chrisley Knows Best” as USA Network’s “most-watched current original series,” with an average of 1.8 million total viewers.

A spokesman for NBC Universal declined to comment on the verdict or on the company’s plans regarding any of the shows. The second half of Season 9 of “Chrisley Knows Best” is still scheduled to air starting June 23.

Following a proven American formula, the show depicts a family with traditional values and a down-home style of self-expression who just happen to be fantastically rich.

In the show’s trailer, Mr. Chrisley describes himself and his wife as people from a “small rural town” who now live in a “gated neighborhood” outside Atlanta alongside “celebrities.” Their “main home” is 30,000 square feet, they spend at least $300,000 per year on clothes and Mr. Chrisley earns “millions of dollars a year” — but the Chrisleys still face the same issues as families making $40,000, he says.

Mr. Chrisley plays the controlling and fastidious patriarch, the sort of father who responds to his son’s misbehavior by throwing his laptop into the pool. His wife’s role is to comment sarcastically yet forgivingly about her husband’s foibles.

The Chrisleys join a growing roster of reality TV stars who have gotten into legal trouble.

In 2018, Michael (The Situation) Sorrentino, an actor in MTV’s “Jersey Shore,” was sentenced to eight months in prison for violating federal tax laws, and in 2014, Joe and Teresa Giudice, two stars of “The Real Housewives of New Jersey,” were sentenced to prison after pleading guilty to bankruptcy fraud, among other charges.

Eduardo Medina contributed reporting.