McDean originally trained and worked as a car mechanic before studying photography. McDean began his photographic career in London as a photographer's assistant to photographer Nick Knight. His early editorial work was featured in magazines such as i-D and The Face, which led to advertising campaign work for clients such as Jil Sander and Calvin Klein, and editorial commissions with Harper's Bazaar and [[Vogue (magazine|Vogue).
His editorial spreads are regularly featured in magazines including Vogue (magazine), W, and Another Magazine. Although primarily a fashion photographer, McDean has photographed portraits of celebrities including Natalie Portman, Joaquin Phoenix, Hilary Swank, Uma Thurman, Gael García Bernal and Nicole Kidman.
McDean is married to stylist Tabitha Simmons. He is represented by Art + Commerce in New York.