Friedman joined the FT during the paper's much-heralded revamp, which was unveiled late last month, from her role as fashion features editor of InStyle UK.
Friedman will write mainly for the FT's Weekend section, which now devotes at least two pages to fashion, in addition to writing occasional stories for the weekday paper.
'We will cover everything from high-fashion trends to grooming and beauty.
The aim is to be as informative, provocative and comprehensive on the subject of getting dressed as the FT is on economics and politics,' she said.
Friedman effectively replaces Holly Finn, who edited the axed How to Spend It pages and left three months ago.
Reporting to Friedman is Edwina Ings-Chambers, who was formerly a fashion writer.
Prior to InStyle, where Friedman worked from November 2000, she was European editor of the US version of Elle magazine from 1996 to 2000.