Right-back agrees one-year deal at the Medway Priestfield Stadium.
Barry Fuller has returned to Priestfield for a second spell after signing a one-year deal.
The right-back, who captained Gillingham to victory over Shrewsbury in the 2009 League Two play-off Final at Wembley, was released by AFC Wimbledon at the end of last season and he joined up with his new team-mates on Monday morning.
On agreeing terms Barry said: “I’m over the moon; I’m excited to be back. The place feels homely, it’s nice to come back to somewhere you know and to be local with my family nearby is important.
“The boys are in good spirits, I’ve played with a couple over the years and the lads have been very welcoming.”
The full-back began his career in the youth ranks at Charlton Athletic before enjoying spells at both Barnet and Stevenage prior to his move to Gillingham in January 2008. He would go on to make 151 appearances across a four-and-a-half year spell before joining Barnet for a second time in August 2012.
He signed for AFC Wimbledon a year later and made a further 233 appearances, scoring one goal.
On capturing his signature manager Steve Lovell said: “Barry is a great acquisition for us; he knows the division very well, he knows this club very well and I think his experience will be a positive influence inside the dressing room.
“He is a hardworking player who will give 100% every time he takes to the field and he provides strong competition for the full-back positions.”