Hackett was brought up and educated in Clifton, Bristol. Having left school at 17 he started full-time work in a local men’s fashion shop. Within a year he moved to London and worked in the fashionable King's Road before accepting a position as a salesman at a tailor's shop on Savile Row. As a sideline he bought and sold second hand clothes purchased from the London street markets and, through this, met up with Ashley Lloyd-Jennings, who shared similar tastes in fashion. Between them they opened Hackett's first store on the King's Road, London.
Hackett quickly grew and leading to Jeremy being well known as an authority on men's fashion particularly in classic style.
In 2007, his book 'Mr Classic' - an anecdotal, incisive, critique of men’s style - was released. The book was well received; bloggers' and critics' reactions were mostly positive. Men’s Health said that “For the man of 2008 who can see that the devil is in the detail, this book is indispensable"  Men's fashion blog The Luxist proclaimed it "a must-have for any man who takes sartorial matters seriously." 
Using online media, Jeremy continues to offer his style advice through the 'Ask Jeremy' portal on the Hackett website.
- Menkes, Suzy (January 11, 2010). "Hackett: A ‘Heritage’ That’s Oh-So-British". The New York Times. Retrieved 2010-10-15.