The roles will stretch across disciplines including technology, marketing, content and retail, it said this morning.
That means it needs to increase the size of its current HQ at Greater London House to 250,000 sq ft. Architects Spacelab are redesigning the building using "bespoke, mobile-first technology" as part of a £40m overhaul.
“Our people are what make ASOS special. We are creating a workspace that fosters creativity, where they can enjoy what they do” said Nick Beighton, the retailer's chief executive.
"Greater London House is such an important part of the company’s history, as well as Camden’s, so I’m thrilled that we get to stay in our home, while building a workplace for the future.”
In October the company reported a 26 per cent jump in sales in the year to the end of August, although profits fell by a third thanks to one-off costs.
Still - it bucked the trend of the overall fashion industry, whose market has shrunk by £700m in the past year, according to research from Kantar Worldpanel.