The 22-year-old, who is expected to go straight into the squad for Saturday's Championship meeting with Sheffield Wednesday, has signed a short-term contract until June 2014 and joins for an undisclosed fee.
Frimpong endured an injury-hit career with the Gunners where, after emerging from the club's academy as a promising young midfielder, knee trouble that required surgery on three separate occasions hampered his progress.
"AFC thank you for the memories thanks for the support thanks for the Love," Frimpong wrote on his Twitter account. "I wish the team wins the league this year.Forever will be in my ❤️”
The Ghana international has previously been out on loan with the likes of Wolves, Charlton and Fulham but has decided to leave Arsene Wenger's side on a permanent basis having spent 13 years with the Premier League club and made 16 senior appearances.
- Sports & Recreation