Elliot was born in Seattle, Washington, as a self-described "Navy brat". He dropped out of high school at the age of 18 and started out in the food business as a dishwasher and bus boy. He attended culinary school at Johnson & Wales University. In the summer of 2010, he changed his name professionally "after a lifetime of confusion and typos", according to his publicist. Elliot and his wife, Allie, have two sons, Conrad and Jedediah. Elliot has another son, Mylo, from a previous marriage.
Elliot's first position following culinary school was at the Mansion on Turtle Creek, a five diamond/five-star property in Dallas, working under Chef Dean Fearing. He then went to The Jackson House Inn & Restaurant in Woodstock, Vermont. It was there that he was named one of the ten Best New Chefs of 2004 by Food & Wine Magazine. Elliot then moved to Chicago to work under the famed Charlie Trotte and Rick Tramonto at TRU. He later toiled at Avenues at The Peninsula hotel, also in Chicago, where he received numerous accolades. Under Elliot, Avenue earned a four-star rating from the Chicago Tribune, Chicago Sun-Times and Chicago Magazine as well as a AAA Five Diamond Award.
In 2007, Elliot faced off against Iron Chef Bobby Flay on the TV show Iron Chef America, with the secret ingredient of chocolate. Elliot narrowly lost to Flay by a total score of 49-47. He afterwards appeared on Today.
In May 2008, he opened the eponymous Graham Elliot, which was his first restaurant and the first bistronomic restaurant in Chicago, Illinois. It received three stars from the Chicago Tribune and two stars in the 2013 Michelin Guide. His flagship restaurant, Graham Elliot, is one of just two restaurants in the city to hold two Michelin stars. Only one Chicago restaurant has received the top honor of three stars. In 2009, he appeared on the TV show Top Chef Masters. In the show, he cooked for The Heart and Stroke Foundation due to his nephew needing a heart transplant. He has been nominated for a James Beard Award three times.
In 2010, Elliot became a judge on the U.S. version of the reality show MasterChef, along with Gordon Ramsay and Joe Bastianich. He also opened his second Chicago restaurant, Grahamwich. He appeared as the Culinary Ambassador at Lollapalooza 2010, a three-day music festival in Chicago, where he cooked for both the public as well as backstage for the performers. Chicago Magazine published an article in which writer Cassie Walker, based on samples served at what had been intended as a tasting party for members of the media, unflatteringly described Elliot's menu offerings. Elliot responded by delivering a profane tweet insulting the magazine. Despite this incident, Elliott was invited to serve Lollapalooza again in 2011.
He is currently a judge for the cooking competition television series Junior MasterChef.