Susannah Constantine, English fashion designer, journalist, and author
Susannah Caroline Constantine (born 3 June 1962) is an English fashion guru, journalist, artist, advisor, television presenter, author, and designer and actress. Her second book, What Not to Wear, co-written with her fashion partner Trinny Woodall, won her a British Book Award and sold 670,000 copies.

Constantine was born into a wealthy family; her father was successful in property and shipping sectors. She was privately educated as a child and went on to date British royalty, David Armstrong-Jones, Viscount Linley, during the 1980s. Constantine has been involved in fashion for a long period, originally working in America for Giorgio Armani and then John Galliano in London. She met Trinny Woodall in 1994, with whom she both proceeded to write a weekly fashion column, Ready to Wear. They founded Ready2shop.com, a dot-com fashion advice business, and wrote their first fashion advice book in 2000, Ready 2 Dress, both of which failed. From there they were commissioned to BBC Two to host the style series, What Not to Wear, from 2001 to 2005. She made regular appearances as a style advisor on The Oprah Winfrey Show and following her success on the shows, she went on to co-host Trinny & Susannah Undress... on ITV in 2006 and Undress the Nation in 2007.

She has co-written fashion advice books with Woodall, some of which have become best-sellers in the United Kingdom and United States. It is estimated that her various style advice books have sold 2.5 million copies in Britain and the United States. Constantine and Woodall have designed their own clothing range for Littlewoods which made its debut in 2007, followed by the release of their latest fashion advice book, The Body Shape Bible.