She fills a vacancy left by Julia Cuthbertson, who six weeks ago moved to a senior writing and associate editor role across the paper.
FT spokeswoman Joanna Manning-Cooper said the doubling up of two senior roles would later be reviewed and was not a cost-cutting move.
Due to the ongoing advertising slump, the paper has an internal head count freeze, but Manning-Cooper added that despite this a new role of deputy editor for FT.com will be created to assist Freeland with the day-to-day running of the online service.
'Chrystia was the best person for the role but still has a very important job to do with FT.com,' she said.
Freeland joined FT.com in October last year from the Globe & Mail in Toronto, where she was deputy editor, and has previously worked in a number of roles at the FT.