After having a successful loan period from Millwall with the Darts at the end of last season, Wood has returned to Princes Park on a permanent basis.
Manager Tony Burman said: “I am pleased that we have signed a good, young defender who can play anywhere across the back line. When Keaton was with us on loan at the end of last season I was very impressed with his attitude and desire to win. Potentially I think we have signed another good prospect for many years to come”.