Winger Lewis Young, midfielder Nick McKoy and goalkeeper Freddy Hall have all signed one-year contracts at Sixfields.
21-year-old Young was a free agent after leaving Burton Albion and according to Cobblers boss Gary Johnson will add 'natural width' to the Town squad.
The versatile McKoy can also play in the heart of the defence and was most recently with Kettering.
International clearance is being sought for Bermudan Hall who has been training with the Cobblers over the past few months under the watchful eye of goalkeeping coach Tim Flowers.