More than 1,000 people queued outside the new Primark store in Belfast when its doors opened on Saturday.
Crowd control measures, including crush barriers, were in place outside the new store at Commonwealth House, which opened at 09:00 GMT.
The retailer has returned to the city four months after a huge fire destroyed its flagship store at Bank Buildings in August.
“It’s like Christmas coming early – I’m ecstatic,” said one shopper.
Another woman said: “I’m from Comber so I have a Primark in Newtownards but this one is the biggest one – it’s Belfast.”
Earlier this week, a temporary walkway was opened to allow eight businesses to resume trading following the fire.
Primark said it was “committed to a long-term future in Belfast”.
“Today marks a significant milestone for our people, our neighbours and the wider community, as we take the first step to get back to business following the fire at Bank Buildings,” said company director Ben Mansfield.
“We are confident that our store and the newly-built walkway will help restore footfall in the Castle Street and surrounding area at this critical time, just before Christmas.”
Primark was extending into Commonwealth House at the time of the fire.
The new Primark store is smaller than the original store, but it still has four floors, 23 cash desks and 25 fitting rooms.
By Mark Simpson, BBC News NI
Primark spent the day handing out free bags and balloons but they are still not ready to offer any interviews.
There is no shortage of questions.
What caused the fire? Could more have been done to prevent it? Who is going to pay for all the disruption?
For more than 100 days, I have asked for an interview.
It is always the same answer: “A Primark spokesperson is not available for comment.”
It is hoped the new store will breathe life back into the city centre following a dip in footfall following the blaze.
Speaking outside the premises on Castle Street, Belfast Lord Mayor Deirdre Hargey said she hoped it would give the city centre a pre-Christmas increase in footfall.
“It’s crucial – this can only help but boost the city,” she said.
“There are challenges ahead with retail but I suppose in the aftermath of what happened at the fire, it allows us to start to reimagine and rethink what we do with our city centre.”
Primark first opened in Belfast in 1975 on Donegall Place.
Meanwhile, another new store opened in Belfast on Saturday – discount department store Guineys has moved into the former BHS site in Castle Place.
Guineys specialises in homeware and clothing, and it has 11 stores in the Republic of Ireland.