The Wales Under-21 international recently made his Premier League debut as a substitute in the 3-1 defeat at Norwich, having impressed when called upon during last season's promotion campaign.
The 20-year-old has come through the youth ranks with the south Wales club and is pleased to have agreed terms.
He told the club website, www.swanseacity.net: "I am delighted to have agreed a new contract. I've really enjoyed being part of the squad and I feel I am developing all the time.
"It was always my dream to play for my home town club, so you can imagine what playing for the club in the Premier League means. It was only a brief appearance against Norwich, but it was an amazing experience despite the result."
Swansea manager Brendan Rodgers has also strengthened his backroom staff with the arrival of Glen Driscoll in the role of performance consultant.
Driscoll, 36, recently left Chelsea after 10 years ar Stamford Bridge, during which he worked with the likes of Jose Mourinho, Guus Hiddink and Carlo Ancelotti.
Driscoll will oversee and support the medical and performance departments at the Swans until further notice, and he is already working to solve the nerve problems that have affected skipper Garry Monk.
Rodgers said: "He's got a great background and tremendous experience and expertise.
"He is unique in the fact that he is a specialist in both medical and physical conditioning. His expertise will help both departments of the club and his arrival is a massive boost for us."
Source: PA
Source: PA