The first Enterprise train left the station at 8.05am on a journey to Dublin Connolly Station.
The rail line also reopened between Belfast and Lisburn, which had been closed for a period of time.
An hourly Enterprise service between Belfast and Dublin is planned to start on Tuesday October 29.
Watch: The first Enterprise train testing takes place at Belfast Grand Central Station
Among the eager crowds at the station this morning to see the trains arrive and depart were the McGarrity family from Dunmurry.
“We have been looking forward to this for a long time, we have a wee train enthusiast in the family and it’s a moment in history so we wanted to make sure we were on the first train,” Kirsten said.
Three-year-old Lorcan arrived at the station dressed as popular children’s character Thomas the Tank Engine.
“It was his idea, he just loves the train, we live right beside it so that’s maybe where he got his love from.
“He really loved the journey, I think maybe he got it confused with the Polar Express though, he just kept saying all aboard,” Kirsten added.
The ride was also nine-month-old Erin’s first time on a train.
“The trains had been closed so she never really got the chance until today but she got on well, she was just busy nosying,” Kirsten said.
“It’s nice to go out on day trips to the likes of Bangor and Whitehead and places, we were still trying to go there driving in the car, but getting the train feels more like a family day out,” Kirsten said.
The McGarrity family- Eoin, Kirsten ad their two children Lorcan and Erin
Belfast’s £340 million Grand Central Station formally opened on September 8, with bus services moving from the Europa Bus Station to the new station at Weavers Cross.
John Douds from Helen’s Bay said he was excited to see a return to rail services from the station.
“I’ve just come down from the first train from Bangor, I’m very impressed with it.
“I noticed when I was on the train, normally you have a thing that tells you your next stop but today it just said ‘welcome’ and I thought that was a lovely touch.”
John hopes the new station will encourage more people to use the buses and trains.
“I think it will open it up for more people, I was looking around and I was quite surprised to see all the places I can go to,” he said.
John Doads
Haylee Revera and Devon Vasque are two Americans currently travelling across Europe, the pair happened to be staying in Northern Ireland just in time to see the trains beginning at the station.
“We didn’t even realise this was the opening. We came in and there were so many conductors, I said: ‘Is there some sort of convention on or something?’ But it’s so great to be here and see it,” Haylee said.
The pair were getting the train from Belfast to Dublin for the next part of their Europe tour and praised Translink for making the journey so easy.
“It’s a great train station, it’s the sort of thing you would expect to see in a big city, it was very easy to get our tickets booked and sorted,” Devon said.
Speaking at the opening Sinn Fein’s Infrastructure Minister John O’Dowd said: “This is another significant step in the development of our public transport offer.
“Belfast Grand Central Station is the largest transport facility on the island of Ireland with the capacity to cater for 20 million passenger journeys a year. With eight rail platforms and 26 bus stands this new facility demonstrates how infrastructure can transform and make a difference,” he said.
Infrastructure Minister John O’Dowd opens Belfast Grand Central Station
Chris Conway, Translink Group Chief Executive is excited to see how the new station will benefit Belfast.
“The commencement of rail services at Belfast Grand Central is a significant milestone in the transformation of public transport in Northern Ireland, providing integrated services which connect people and place,” he said.
The Translink chief hopes the new station can help encourage more people to use public transport.
“The first Enterprise departure at 8.05am today was a truly historic moment, marking the start of rail services at this iconic new facility and the return of cross border rail services to the heart of the city.
“With new rail timetables in place and many new features at the station including new ticket gates, we would encourage passengers to plan ahead and build in a bit of extra time for your journey until you familiarise yourself with the new station.”