Carson was previously with Blackburn Rovers and scored 14 goals and was named Player of the Year as Morpeth won the Evo-Stick East Division title in 2018/19.
Caley Thistle boss John Robertson told the club website: “David is very neat on the ball, takes care of it well and aggressively tracks back if he loses it. He also has an eye for a goal and I am looking forward to integrating him into the squad.”