Mary Margaret Portas OBE (née Newton; born 28 May 1960) is an English retail consultant and broadcaster who hosts retail- and business-related television shows. Portas was appoined by David Cameron, the British Prime Minister, to lead a review into the future of Britain's high streets.

Portas was the fourth child of five siblings, born into a Catholic and Protestant Irish family in a small end-of-terrace in Windsor Road in north Watford. She attended Holy Rood Catholic Junior School (in north Watford) and then St Joan of Arc, a Catholic grammar School in Rickmansworth. Her Fermanagh-born Catholic mother died of encephalitis when Portas was 16. At 18 Portas turned down a place she had won at the Royal Academy of Dramatic Art to look after her younger brother. Her father soon remarried but died of a heart attack two years later. He left his house to his wife, leaving Portas and her brother homeless, relying on the kindness of other people, and living with family friends.

Portas started her career in retail with a Saturday job in John Lewis. She then had a part-time, and later a full-time, job with Harrods where she was responsible for window displays for about three years, before joining Topshop as display manager. While in this job, she was spotted by Burton Group chairman Ralph Halpern.

Her next role brought Portas her first taste of fame and public acclaim, as creative director of Harvey Nichols. Portas is credited with turning Harvey Nichols into a leading modern fashion brand. She created the Harvey Nichols window displays that became part of the guided tours of London, one of her most famous displays was "Autumn Intrusion", a commission by artist Thomas Heatherwick that won a D&AD Gold award in 1997. She then persuaded the store's owners to use younger designers, and gained publicity in the BBC's Absolutely Fabulous series in the 1990s, after promising writer and star of the show Jennifer Saunders the run of the store for research in return for Saunders namechecking the business. By the age of 30, Portas was a member of the company's board.

In 1997 Portas left Harvey Nichols to launch an agency, Yellowdoor, producing campaigns for clients including Clarks, Louis Vuitton, Oasis Stores, Swarovski, Dunhill, Boden, Thomas Pink, Patek Philippe and Mercedes-Benz, Sainsbury's, Habitat, Westfield, Liberty and The Body Shop.

Portas is claimed to be one of the UK's foremost authorities on retail and brand communication. She regularly travels around the world advising on retail strategy and frequently lectures on the theme of brands and retail. Notably, Portas spoke alongside Neil Armstrong at the Cannes Palais Festivals in October 2007, and spoke at the Yorkshire International Business Convention with the Dalai Lama in June 2012.

On 19 June 2009, in a ceremony at Galashiels, Heriot-Watt University awarded Portas a Doctorate of Letters in recognition of her career and her contribution to the advancement of marketing and brand communications within the retail sector

In December 2009, Portas opened her first permanent 'Living & Giving Shop' in support of charity Save the Children. As of 2025^[update] there were over 21 shops open, mostly across London. She was also named as the charity's Global Retail Ambassador. By 2019, the charity shops have raised in excess of £23m for Save The Children. Portas has been credited with revolutionising the charity shop store format, making "Mary's Living & Giving" a destination for second hand and pre-loved clothing and separating it from the rest of the category - "Charity shops with a difference".^{[citation needed]}