The 33-year-old former Birmingham City, West Bromwich Albion and Preston midfielder, who made 368 Football League career appearances, becomes Solihull's sixth signing of the summer.
The Moors have so far signed three strikers, Shomari Barnwell, as well as Luke Benbow and Chris Lait.
They also signed utility player Jack Edwards and full-back Kalern Thomas.
Boyhood Birmingham City fan Carter has made 392 league and cup appearances in his career, with the former Sunderland and Millwall loanee playing in four of English football's top five tiers.
He played for Birmingham and Albion in both the Premier League and the Championship, and has more recently been in League Two with Cheltenham and Northampton.
Last season Carter played in the National League with Forest Green, helping them gain promotion to the fourth tier, but he has never played in League One.
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Solihull Moors have signed experienced midfielder Darren Carter following his departure from promoted Forest Green.