The £61million retail development, opposite the successful Buchanan Galleries, is expected to open for business next March.
Owners Land Securities say the development is "99% let or in solicitors' hands" with high street names including Paperchase, Gap, Fat Face, Skechers, Office and Watches of Switzerland lined up to move in.
For Paperchase, this will be the brand's first flagship store in Scotland and it will take up about 17,000sq ft.
Gap will operate a 12,000sq ft store joining Forever 21's 60,000sq ft 'anchor' flagship store.
Linda Chang, global marketing director for Forever 21, said: "We are always looking for unique retail spaces to complement the brand. We are excited to open our first store in Scotland where we will be able to offer all of the latest trends to Glasgow's most fashionable shoppers."
The new Buchanan Street development will sit opposite the highly successful Buchanan Galleries, also owned by Land Securities.
Buchanan Street will offer 155,000sq ft accommodating nine outlets and its owners say it is perfectly positioned to draw on a high level of footfall in the area.
The street has one of the UK's strongest flows of footfall, second only to Oxford Street in London, with an average of 6138 people per hour.
The development is expected to open a day after Land Securities open a similar large retail venture in Leeds.
And Lester Hampson, head of retail development at Land Securities added: "Land Securities is bringing an extra two kilometres of retail frontage to the UK market in one day.
"Our confidence in the success of both the Trinity Leeds and Buchanan Street schemes sends a very clear message to the international market: the UK economy is growing, and is open for business.
"With our unrivalled knowledge of the retail market, Land Securities is the partner of choice for ambitious retailers."
The development further strengthen's the city's reputation as the second largest retail destination in the UK after London.
It will create a new prime pitch in Buchanan Street, one of the busiest high streets in the UK. The US fashion brand Forever 21 is the largest shop letting on Glasgow's busiest shopping thoroughfare.
Land Securities is the UK's largest commercial property company and a member of the FTSE 100.
The company owns and manages more than 29million sq ft of property, from shopping centres to offices.