The SPL had just come out of a transfer embargo, and they have moved quickly to bring in Wilson.
Hearts have now confirmed that Wilson had joined on a six-month deal and could play against Clydesdale Bank Premier League champions Celtic on Saturday.
The former Rangers defender has struggled to win a first-team place at Anfield and has spent time on loan at Blackpool and Bristol City since leaving Ibrox in July 2010.
Hearts boss John McGlynn was delighted to seal his signature, telling the club's website: "Danny is a quality player and someone we know a lot about.
"Even at such a young age, he brings a lot of experience and not only will he be a very good addition to our squad, he will be a good influence on the young players we have here.
"He has been playing regularly down south so fitness won't be a problem and hopefully it won't be long before we see him in a Hearts shirt."