He planned on continuing his studies in medicine, but Barker's mother entered him into a televised model search on The Clothes Show. Barker wound up being a finalist on the show, which started his modeling career. He modeled for around 10 years in London, Milan, Paris and New York City. As a young model, he observed that the fashion industry was changing - that "models were shrinking and a 6’4" well-built male model was not selling". Being adaptable to change and loving the fashion industry, in 1996, he transitioned himself from model to fashion photographer. Barker opened his own photo studio, StudioNB, in the now-fashionable Meat Packing District in Manhattan. Barker has shot editorials for GQ, Interview, Seventeen, Town & Country (magazine), Lucky, Tatler, and Cover. He has shot advertising campaigns for Land's End, Leviev, Nicole Miller, Nine West, Ted Baker, Jordache, Pamella Rolland, Beefeater, Ford, and Sony. Barker was a judge for 17 cycles on Tyra Banks' reality show America's Next Top Model. He was also an official judge for the Miss America Pageant in 2007 and Miss Universe Pageant in 2012. He also serves as executive producer for the VH1 photography-based reality contest, The Shot. In February 2013 Barker became the host of The Face. After a successful first season with supermodels Karolina Kurkova and Coco Rocha by his side, the show is now going into its second season featuring supermodel coach Naomi Campbell, and supermodels Anne V, and Lydia Hearst. Barker made a special appearance as a photographer on the third cycle of Canada's Next Top Model, and in Episode 10 of the first cycle of New Zealand's Next Top Model. Barker appeared as guest judge and photographer on the first cycle of Mexico's Next Top Model. He also made a guest appearance on the second cycle of Benelux' Next Top Model. His directorial debut was a highly acclaimed documentary that he also produced called, A Sealed Fate? - followed by, Generation Free and Haiti: Hunger and Hope, which partner with respective charities: The Humane Society of the United States, the Elizabeth Glaser Pediatric AIDS Foundation and the Edeyo Foundation, to highlight some of our world’s most pressing issues. Additionally, Barker is a celebrity ambassador for the Make-A-Wish Foundation, Do Something, The United Nation Foundation's Girl Up initiative and campaign shooter for Fashion Targets Breast Cancer. Barker holds spokesperson positions for prominent brands including, Microsoft, Sony, Crest White Strips and Nine West. Barker appears alongside Justin Timberlake and Peyton Manning in Sony's 2010 national ad campaign. In addition, he has lent his personality to television and feature film cameos, event hosting and presenting. Barker appeared as a celebrity judge for the 2008 Miss America Pageant and had cameo roles on several TV series including, The Young and the Restless, Privileged, Stylista, Style Her Famous and Ugly Betty, as well as a cameo role in the feature film Arthur (2011), with Jennifer Garner, Russell Brand, Nick Nolte and Helen Mirren. He has hosted and presented for many events including 2007, 2008 and 2010 Emmy awards on Fox Broadcasting Company, the 2008 and 2009 Go Green galas in New York City, the Genesis Awards and the 2010 Global Fashion Awards. In 2017, Nigel Barker became New Zealand winery Invivo's official "glambassador"  Barker published a book on beauty, Nigel Barker's Beauty Equation: Revealing a Better and More Beautiful You, released September 2010, from Abrams Image. The book guides the reader through a series of self-portrait and journaling challenges, which help the reader to discover their inner beauty by building confidence and self-esteem and in turn, enhance their outer beauty.  In January 2009, Barker opened a photography exhibit, Haiti: Hunger and Hope, at the Milk Gallery in New York City. His work in Haiti earned him a Do Something with Style Award nomination from the VH1 Do Something Awards. The awards show, produced by Vh1, is dedicated to honoring people who do good and is powered by Do Something, an organization that aims to empower, celebrate, and inspire young people. Barker teamed up with Taylor Swift to shoot a photobook of the young superstar titled 8 hours which made its debut in November 2012. In September 2013 Barker shot Nadia Lacka, Liliane Ferrarezi, Jordan & Zac Stenmark in 'Bedtime Stories' featured in the September issue of Numero Russia.