The official Ponty website has confirmed 32-year-old will make the move from Worcester at the end of the season.
Jones, who won 10 caps for Wales, played for Cross Keys, Pontypridd and Ebbw Vale before joining Gloucester in 1998.
His move is expected to be announced officially when Ponty announce their team ahead of the Parker Pen Shield final against Sale.
The Bedwellty-born flanker's signing adds to the Ponty recruits for next season, following Emyr Lewis (Newport), Paul Jones (Cardiff), Geraint Lewis (Swansea) and Phil Edwards (Uwic) to Sardis Road.
Meanwhile, Cardiff have ended a nine-month chase for Bristol's Jim Brownrigg, after the back-rower agreed a two-year deal to move to the Arms Park.
The 24-year-old impressed the Blue & Blacks' management when he spent a short time in Wales at the start of the season.
He played in victories over Newport and Caerphilly, but had to return to Bristol when the Shoguns suffered an injury crisis.
Cardiff kept a close watch on Brownrigg after that and, now he is out of contract, made their move.
"I really had a great time at Cardiff at the start of the season. It is a great club, and I enjoyed their style of rugby and their supporters," said Brownrigg.
"But I know there is no guarantee of first-team rugby, you have to earn it."