Walker was born in England in 1970.[4] His interest in photography began at the Condé Nast library in London where he worked on the Cecil Beaton archive for a year before college.[4] After obtaining an HBC in Photography at Exeter College of Art and Design, Walker was awarded a third prize as The Independent Young Photographer Of The Year.[5]
Upon leaving college in 1994, Walker worked as a freelance photographic assistant in London before moving to New York City as a full-time assistant to Richard Avedon.[4] When he returned to England, he initially concentrated on portrait and documentary work for British newspapers.[5] At the age of 25 he shot his first fashion story for Vogue, and has photographed for the British, Italian, and American editions.[4] He has also shot notable covers for W Magazine, i-D, Vanity Fair, Another Man, and Better Homes and Gardens Magazine.[3][6]
Walker's Wonderful Things exhibition at the Victoria and Albert Museum, London in 2019–2020 consisted of 10 rooms containing new projects, each one inspired by various artefacts from the V&A. Over the course of three years, Walker visited the V&A’s numerous storerooms, met with curators and technicians, even scaled the roof of the museum and climbed through the Victorian passages underneath it, in search of the items that would inspire each series.[8][9]