Centre Adam Jones joins from Championship winners Ebbw Vale while Ceri Young is a full-back who has signed from Newbridge.
Both players scored tries for fun in the Championship last season with Jones also a proven goal kicker.
Head coach Neil Edwards said: “These two players were the best in their position in the Championship last season. They are two up and coming players and I am confident they will have no issues in stepping up to Premiership level.
“We look forward to welcoming them to The Gnoll for pre-season and they are both looking forward to joining the squad.”
The club have also retained the services of outside half Dai Langdon and tight head prop Marc Jones for next year’s campaign.
For free-scoring Langdon, it’ll be his fourth year at The Gnoll and with almost 600 points scored for the Blacks over the last three years, the 24-year old will be keen to add to his impressive kicking record when the new season starts.
The 31-year old Jones will start his second season in his second spell with Neath after initially rejoining the club from Cross Keys in November last year. A tough prop who takes no prisoners, he crossed the line for his first try for Neath in the last Premiership match of the season against Cardiff.
Edwards said: “I’m delighted that more of our best players from last year are rejoining us again. Everyone who is signing is 100 per cent committed to the club and wants to see us back at the top of the table.
“We’ve a full pre-season ahead of us to make sure everyone is in shape for the 2013-14 campaign where everyone is confident we’ll be successful.”