Ray's family is Italian-American on her mother's side and French-American on her father's side. Her family owned a restaurant in Massachusetts, while her mother managed restaurants in upstate New York. She grew up in Lake George, New York, and her first job was at the candy counter at Macy's in New York City. She helped open Agata & Valentina, a New York City market. Moving back to upstate New York, she managed Mister Brown's Pub at the famed Sagamore Resort on Lake George. From there, she became a buyer and chef at the Cowan & Lobel market in Albany, New York. Ray credits the concept of 30 Minute Meals to her experience working at a gourmet food store where people were reluctant to cook. She began teaching a cooking course showing people how to make meals in thirty minutes or less. With the success of her "30 Minute Meals" classes, Schenectady, New York TV station WRGB, the local CBS affiliate, asked her to continue on their newscasts. This, along with a public radio appearance and the publication of her first book, led to a Today Show spot and her first Food Network contract. She also appeared in a few commercials for Schenectady-based grocery chain Price Chopper, which stocks all her books at their stores and retains her as an occasional spokesperson.

Ray owns homes in Lake Luzerne, New York and Manhattan's Greenwich Village. On September 24, 2005 in Montalcino, Tuscany, Italy, Ray married John Cusimano, a lawyer and member of the band The Cringe.

Ray teaches simple recipes that she claims can be prepared in 30 minutes or less. Like many cooks, she uses garlic and chicken stock as simple ways to boost flavors. She often uses recipes that include her Italian, French, and American heritage. She emphasizes using fresh herbs whenever possible. She states that measuring "takes away from the creative, hands-on process of cooking" and instead favors approximations such as "half a palmful" and "eyeball it." On her television programs she has introduced catchphrases such as "E.V.O.O." (extra-virgin olive oil), "yum-O," "so delish," "G.B." (garbage bowl)," spoonula, stoup (cross between a soup and stew, even though "stoup" is already a real word that means "the holy water receptacle at the front of a church") and "how good is THAT?" She often refers to sandwiches as "sammies."

She claims to dislike baking desserts and to be notorious for burning bread under the broiler. Ray says her Sicilian maternal grandfather, Emmanuel Scuderi, served as a strong influence on her cooking. To critics of her shortcut techniques, Ray responds, "I have no formal anything. I'm completely unqualified for any job I've ever had."

Ray launched her own magazine, Every Day with Rachael Ray in conjunction with Reader's Digest. The magazine premiered on October 25, 2005 and will feature seven issues in 2006. It will increase to ten issues in 2007.

In addition to her television hosting and cookbooks, Ray has endorsed products for Price Chopper supermarkets and Burger King, and has developed her own line of cookware and cutlery. When she endorsed Wüsthof's, sales rose dramatically, and she now endorses her own line of santoku knives.[5] In 2003, she posed for the men's magazine FHM. The New York Times wrote, "The shots feature Ray in short-shorts with an exposed midriff, licking chocolate off a big wooden spoon, eating a strawberry and sitting in a sink, laughing as suds cascade down her curvaceous thighs." A year later, she was named number 92 on "FHM-US's 100 Sexiest Women 2004". Most recently, she was featured as #71 in "FHM-US's 100 Sexiest Women 2006".

In late 2005, Ray signed a deal with Oprah Winfrey and King World Productions to host a syndicated daytime TV talk show. The show, Rachael Ray premiered on September 18, 2006. Recurrent appearances on The Oprah Winfrey Show were used to fuel the launch, much like Dr. Phil's show was spun off based on his own frequent visits to Oprah.[6] The show tapes in New York City, and Ray will continue to appear on the Food Network. Ray said, in coordination with the syndication announcement, "People know me for my love of food, but I have so much more I want to share." On the September 19th episode of The Insider, host Lara Spencer characterized the ratings for the show as "a monster hit".

In addition to Oprah, Ray has appeared on The View, The Today Show, The Tonight Show with Jay Leno, The Late Show with David Letterman, Late Night with Conan O'Brien, and Larry King Live.

In 2006, Ray's 30 Minute Meals received an Emmy Award for Outstanding Service Show. Ray was also nominated for Outstanding Service Show Host, but lost to Suze Orman.

Ray was also named one of Time magazine's 100 most influential people of 2006. She was nominated by fellow Food Network star Mario Batali.

According to Forbes magazine, Ray earns about $6 million a year from her books and television shows.

On November 12, 2006 Mario Batali and Rachael defeated the team of Bobby Flay and Giada De Laurentiis on an episode of Iron Chef America.

In November 2006, Rachael became a spokeswoman for Nabisco crackers. She appears in commmercials and on boxes for the many Nabisco products. Many boxes with Rachael's picture have recipes written by her.

In the episode of the animated show Metalocalypse titled Religonklok, Toki Wartooth, one the show's main characters, tells of his great disliking of Ray (and Food Network in general), and prays for something bad to happen to her at a Church of Satan.

Some have criticized Ray's perky demeanor as well as her lack of a formal chef's education and perceived unseriousness about cooking. For example, celebrity chef and Travel Channel personality Anthony Bourdain has referred to her as a "bobblehead".

In a Slate article defending Ray, Jill Hunter Pellettieri summarized these criticisms by writing:

"Ray's ditzy demeanor also makes her easy to dismiss. She giggles off-cue and constantly praises her own cooking. "Smells awesome already!" she says, making her Snapper in a Snap. "I am so psyched about that." She employs kitschy abbreviations—EVOO means "extra virgin olive oil"—and gives her menus corny nicknames like You-Won't-Be-Single-for-Long Vodka Cream Pasta. The acknowledgments in her $40 a Day cookbook read like a high-school yearbook: "Don …You are the tallest man we've ever had on crew, and yet you pack the smallest bag—ever! Cool." And it didn't boost her credibility when she posed for pinup shots in FHM. (One featured Ray licking chocolate off a spoon.) When the magazine hit newsstands, she said, "I think it is kinda cool for someone who is goofy, and a cook, just a normal person to be thought of in that way.""