Grigson was born in Swindon, Wiltshire in 1959 and attended Oxford High School. From there she went on to study mathematics at UMIST, Manchester. After graduating in 1982 with a Bachelor of Science degree in mathematics (she was Vice President of the UMIST Alumni Association), she worked for a time as a production manager of pop videos for groups including Bonnie Tyler and the Style Council. Having inherited her mother's love of food, she found she also enjoyed writing about it. Her first food article, published in 1983 in the Sunday Express Magazine, was entitled Fifty ways with potatoes. She has since written columns for the Evening Standard, The Independent, and The Sunday Times.

Grigson' television debut came in 1993 with the twelve-part series Grow Your Greens, Eat Your Greens on Channel 4. Her more recent television work includes Sophie Grigson in the Orient and Sophie Grigson in the Souk for Travel Channel.

She won the Guild of Food Writers Cookery Journalist Award 2001. She is a keen supporter of organic and local food suppliers and, like Jamie Oliver, is an advocate for decent children's food. She is a patron of the Children's food festival. Sophie Grigson now runs food and wine tours in association with World of Experience Tours. She was previously married to William Black and they had two children, Florence and Sid.