Now 32, the midfielder has put pen to paper on a two-year deal which will see him return for a third spell at the club, having also spent time on loan in South Wales in 2011.
Ramsey's move to the Cardiff City Stadium comes after he was released by French outfit Nice earlier on Saturday, having spent one season at the club during which he made 34 appearances.
The Wales captain spent 11 years at Arsenal after leaving Cardiff for the first time, and has since had stints at Juventus and Rangers too.
«It feels unbelievable to finally be back here. I always thought one day I'd come back, and now it's the perfect time to do that,» Ramsey told the club's official website.
«To be back with my family and around familiar faces is just brilliant, so I'm delighted to be back here now. I've missed that a lot in the last year or so, so it was important for me to be back around them.
»Obviously I'm a Cardiff City fan, and watching them over the years since I've been away, we've had some low points but some big highs as well, being in the Premier League and representing Cardiff on the big stage. That's a target of mine — to try and help my teammates and this club to get back to the top.
«I've said it many times in the past — I owe so much to Cardiff, to the fans, to everybody who has been at the club when I was here as a young boy coming through.
»For me now to come full circle, to be part of this team now, and hopefully achieve the goals we want, there's no better feeling than that."
Cardiff manager Erol Bulut added: «This is, of course, a great day. Aaron started here, and now he is back to help us to achieve our targets.
»First of all I want to
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