The fulfilment centre in Union City, outside Atlanta, is expected to be operational by next year and will help the firm to further tap the market for young shoppers.
Asos said it will “significantly enhance” its US proposition by providing more cost effective, faster and more flexible delivery options.
The company currently has a small fulfilment centre in the US which manages 25% of all stateside orders, with the remainder being dispatched from the UK.
The 10 million unit capacity facility is part of the retailer’s plan to refocus on the core markets of the UK, Europe and the US.
Boss Nick Beighton said: “This agreement is a major step forward for Asos in the US and demonstrates the opportunity we believe lies ahead in this key market.
“Our US fulfilment centre will enable us to significantly develop our proposition for our 20-something US customers supporting our continued growth and future ambitions.”
The firm’s US business delivered 39% constant currency growth in the first six months of 2017 following sales of £179 million in the year ended August 2016.
Earlier this year, Asos revealed it was planning further investment at its giant distribution centre in Barnsley, South Yorkshire.