Northants will have two England spin bowlers on the staff next summer with Richard Dawson joining Monty Panesar at the County Ground.
Dawson and the other signings have agreed one-year deals
Dawson, who was recently released by Yorkshire, is the most high profile of four signings made by the club.
The 26-year-old has made seven Test appearances, but none since the 2002-03 Ashes tour to Australia.
Batsman Andrew Crook and seam bowlers Richard Logan and Richard Browning will also be joining Northants in 2007.
Crook will be linking up again with his brother Steven after being frustrated by a lack of first-team opportunities at Lancashire.
Logan, meanwhile, returns to Northants after six years with Notts and Hampshire and his arrival will compensate for the recent departure of Ben Phillips to Somerset.
Browning is one for the future at just 18 years old and has been picked up from the Derbyshire academy.
"I am pleased to sign all four players. I see them complementing and strengthening the squad during the 2007 season," Northants coach David Capel commented.