The 27-year-old is a product of the Newport Gwent Dragons Academy and Age Grade System, who has international caps at Wales U20s level.
Originally from Pontypool, the highly rated individual has made 100 appearances for Ebbw Vale and is a firm fan favourite at Eugene Cross Park.
Last season saw Sweet train with the Newport Gwent Dragons Premiership Select squad and play for them during the British and Irish Cup competition, in which he showed great potential.
After signing his contract with the Dragons, Ashley Sweet commented: “I am delighted to have signed with the Dragons. I began my journey as part of the academy system and playing alongside the U16s all of the way through to the U20s and I have never given up on playing professionally for my home Region.
“It will be an honour to contribute to a successful Dragons side in the future and I would like to thank Kingsley for this opportunity.”
Dragons Head Coach, Kingsley Jones added; “We are happy to be welcoming Ashley to the Dragons, he is a player with all the characteristics to play at Regional level.
“He performed extremely well for the Dragons Premiership Select Team in the British and Irish Cup and is the sort of person who will add to our environment - He has earned the right to be given an opportunity at Regional level.
“I look forward to Ashley taking this opportunity, showing his full potential and establishing himself within the squad.”
Sweet is one of a number of new faces that have joined the Dragons during pre-season, including newcomer’s Nick Macleod, Darran Harris, Sam Beard, Pat Howard, Tom Davies, Sam Hobbs and Craig Mitchell.