The experienced Nottingham-born player, who has also had spells at Sheffield Wednesday and Bradford City, is expected to pass a medical that will complete his move to Whaddon Road today.
"I'm really pleased to have reached this agreement with Craig," Cheltenham manager John Ward told the club's official website.
"He's a player with a number of strings to his bow and he will give us a nice balance to the team. He's a left-sided player who can play in midfield or at left-back."
County boss Gudjon Thordarson was understandably disappointed at the 30-year-old's decision, but refused to get too down-hearted.
"I am disappointed things didn't work out," Thordarson told the Magpies' official site.
"He is a good player and we didn't agree terms first time around. Although we looked into it yesterday, it won't happen now and I wish him well.
"I have a few other targets in mind so I am not going to worry about it," added the Iceman.