The 437,000sqft centre just outside Lichfield will employ 2,000 people over the next three years, the business said.
It will open within the next 12 months and is expected to reach peak trade by 2023.
The Lichfield fulfilment centre will be the company's fourth. It already has sites in Barnsley, Berlin and Atlanta.
In October, ASOS reported a 329% rise in annual profits after sales held up thanks to demand for casual clothing and sportswear during lockdown.
Revenues rose 19% for the year to the end of August - a slight slowdown compared to the 21% growth in the first half of the year, with smart and "going out" clothes becoming harder to shift.
The group faced higher costs to implement safety measures at warehouses but saved money as "more deliberate purchasing behaviour" from customers meant fewer items were returned.
ASOS saw slowing growth over the summer and government restrictions aimed at limiting the spread of the coronavirus pandemic resulted in lower demand for occasion wear.
The retailer said it had instead expanded its casual wear offering to adapt to the "shift in 20-something lifestyle".