Tiffin replaces Peter Howarth, who is leaving the magazine in December to pursue other interests including finishing his novel. Howarth, who handed in his notice in September, will be retained on a consultancy basis.
Tiffin has worked in the men's publishing sector for 12 years in which time he has worked as chief sub editor and sports editor at Conde Nast's GQ. In 1996, he was appointed deputy editor for the launch of spin-off title GQ Active and became editor in 1998.
He joined NatMags' Harpers & Queen last year.
Duncan Edwards, managing director of NatMags, said: "Simon's appointment is the result of us having considered some of the best talent in the men's and women's magazine business.
"The modern Esquire has successfully carved out a distinctive grown-up positioning in the rather juvenile men's market, with quality journalism at its core. We have the very best product in this market and I know Simon will develop and enhance this unique brand."
Esquire recorded an ABC circulation of 62,005 in the last set of figures for the January to June 2002 period, unmoved on the previous quarter.
The magazine sits in 10th place in the UK men's market. However, it is seen as a more sophisticated read than the titles at the top of the list such as FHM and Loaded and competes more with Emap's Arena.
Arena had a circulation of 38,000 but an ABC investigation recently showed that it has infringed rules on bulk copies and is having to restate its figures.
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