She made her Broadway debut in the musical ''Don't Get God Started, after which she and fellow students created Stage Three, an off-Broadway acting troupe. When they brought one of their productions to Los Angeles, Heaton caught the eye of a casting director for the ABC drama thirtysomething, leading to three appearances on the series. She was featured in three unsuccessful sitcoms - Room for Two (1992) with Linda Lavin, Someone Like Me (1994), and Women of the House (1995) with Delta Burke - before landing the plum role of beleagured wife, mother, and in-law Debra Barone in Everybody Loves Raymond'' (1996 - 2004) with Ray Romano. Since 1999, she has been nominated every year for an Outstanding Lead Actress in a Comedy Series Emmy, winning the award twice. She has also collected two Viewers for Quality Television awards and a Screen Actors Guild trophy for her work on the series.
Heaton is the honorary chairperson of Feminists for Life. This nonsectarian, nonpartisan organization is opposed to domestic violence, child abuse, infanticide, and abortion.
Heaton has been married to British businessman David Hunt II since 1990. The couple has four sons and divides their time between Los Angeles and England, where they own a country estate. She also had a brief marriage (84-87) that ended in divorce.
Since 2003, Heaton has appeared in a series of humorous television and radio commercials as spokesperson for the Albertsons grocery store chain.
While Heaton has been quoted as saying "...once a Catholic, always a Catholic...", according to her book and following interviews, she currently attends a Presbyterian church.