The young defender secures a dream move to join Premier League giants Manchester United, for an undisclosed fee.
Regan became the youngest player ever to represent Newport County AFC, when he made his debut against Shrewsbury Town in September 2014, aged sixteen and ninety-four days.
Regan then went on to play a further eleven times for Newport during the 2014/15 season, leading to the youngster being shortlisted for the Football League apprentice of the year award.
So far this season the centre-back has made three appearances, the most recent coming in our home defeat against Leyton Orient.
At international level Regan has been been capped at under-17 level by Wales, making his debut against Montenegro in October 2014.
Manager Terry Butcher admitted that a number of clubs had shown interest in Regan over the past few days, but once Manchester United declared their willingness to sign the defender it would have been difficult to turn down.
"In the past few days a number of clubs have shown an interest in Regan, but as soon as Manchester United came in there was only really going to be one outcome."
"It is every boy's dream to play for Manchester United, and it's a wonderful opportunity for him to progress at such a magnificent club. It doesn't matter which country you are in, or where you are in the world, when Manchester United come calling you have to answer."
"What it does show for our club is that there is a pathway right to the very top. Someone like Regan, who started of at Cardiff but was released and then came to us, it doesn't matter which age the players come to us they can emulate Regan's footsteps."
"It's a great boost for the club, in terms of the academy, the first team and the area of Newport. The region produces a lot of good, young footballing talent."
"We are active in the transfer market and there will be options for us when the loan window re-opens again in a week's time. There is a small legacy in many aspects that Regan has created, the money that he has generated could help to get other players and to give the younger boys that inspiration to possibly do what he's done one day."
Newport County AFC would like to thank Regan for his efforts during his time at the club and wish him all best for the future.