Born to Kurt and Lenore Riegel on New Year's Day in Washington, D.C., 1981, Riegel was raised in a Virginia suburb and became interested in acting while watching her brother, Sam, perform dinner theater, which she later joined in for $10 a week. Her big break came when she won the role of Cosette in Les Misérables, leading to other roles on and off-Broadway. She graduated from the Professional Children's School and attended Harvard University, with ambitions to become a lawyer, but later left the institution. In 2000, she served as an intern at the White House for the summer.
From July 2000 to February 2005, Riegel portrayed the role of Bianca Montgomery on the American ABC soap opera All My Children. During the 2004-2005 baby switch storyline, when Bianca's daughter is kidnapped and switched with the son of Babe Carey Chandler (Alexa Havins), Riegel also portrayed Bianca on fellow ABC soap opera One Life to Live. In December 2000, Riegel's character "comes out" to her mother, Erica Kane (Susan Lucci), becoming the only lesbian on a daytime soap opera at that time. In 2003, the kiss between Bianca and character Lena Kundera (Olga Sosnovska) made history when it became the first lesbian kiss to appear on American daytime television. In 2005, with Lena out of the picture, Bianca shares a kiss with close friend and confidante Maggie Stone (Elizabeth Hendrickson), making TV Guide's list of best same-sex kisses on television. Riegel's character was awarded the first Gay & Lesbian Alliance Against Defamation award for "Favorite OUT Image of the Year" in 2004. Lesbianation.com, self-proclaimed as the leading online community for lesbians, voted Eden Riegel as Number 7 on their top ten list of Women We Love: The Ladies of June '06, stating, "We were swamped with requests to add All My Children hottie Eden Riegel to our list this month — and here she is!"