Johnson has been quarterbacks coach for the Minnesota Vikings for the past three years, but will move into a new role with the Giants, taking charge of their running backs.
He is into his 15th year of coaching in the NFL, with Giants head coach Tom Coughlin declaring that Johnson can provide valuable experience.
Coughlin told the team's official website: "This is a veteran coach that has coached some great players, such as Steve McNair. He's been around a while and has experience as a quarterbacks coach, as a running backs coach and he's been a coordinator in college.
"I think he is an excellent teacher and his versatility is going to add a lot to our staff and, of course, to the running backs room. His interview was very impressive as we put him on the board and he really did an outstanding job with protections.
"He's also talked long and hard about ball security. Pass protection and ball security are both very important to me."