In a letter posted on the gossip Web site Gawker.com and reported in New York newspapers on Thursday, Stewart wrote that her lawyers advised her that it would be appropriate for supporters to write to Judge Miriam Goldman Cedarbaum.
"If you would be so kind to write such a letter, please include your opinion of my character, my work ethic, my integrity and my probity," Stewart wrote. She added that writers could include "any memorable experiences you have had with me" to explain the basis of their opinions.
"I deeply appreciate all of your good wishes and support," she wrote in the letter, which was dated March 12. "Of course, your support means a great deal to me and my family."
Stewart reportedly sent the letter to about 100 of her friends and acquaintances.
"It is standard practice ... to explain to people who've expressed interest in writing letters of support how to go about doing it," George Sard, a spokesman for Stewart, told the New York Post, Daily News and Newsday.
Stewart, who resigned from the board of Martha Stewart Media and stepped down as the company's chief creative officer on Monday, is set to be sentenced June 17.
Most legal experts expect her to receive a sentence of 10 to 16 months in prison, although a judge could allow her to spend some of that time at a halfway house or in home confinement.
Stewart and her stockbroker, Peter Bacanovic, were convicted of lying to investigators, obstructing justice and other charges related to Stewart's sale of ImClone Systems stock on Dec. 27, 2001.
The government claimed Stewart and Bacanovic lied when they said they had a pre-set deal to sell the stock when it fell to $60.
Stewart's lawyer conceded she sold because she was tipped that ImClone CEO Sam Waksal was unloading his shares — although he insisted Stewart was accurate when she said in 2002 she did not recall the tip.
Her Web site about her legal troubles, marthatalks.com, reports that she has received 35,000 supportive e-mail messages since the verdict was announced March 5.