The 27-year-old, who has been capped twice for Scotland, played for both Dundee and Dundee United, and moves to Easter Road following a brief spell with the Tangerines.
Robertson told Hibs' official website: "This is a great move for me and I'm really excited about what we can achieve at Hibs.
"The club has made a decent start to the season and we are in a strong position in order to be able to kick on and progress even further.
"There were other options on the table, but as soon as I spoke to Pat Fenlon I was convinced that Hibs were the right club for me."
Hibs boss Fenlon says he was extremely pleased to be able to add Robertson to his playing staff.
He said: "Scott will be a valuable addition to our squad - he is a skilful box-to-box midfielder, who is strong in the air and can provide goals.
"He is a player, who has been on our radar for a while, so we were pleased to be able to get the deal over the line.
"Again, Scott has signed until the summer of 2015 which brings continuity and we believe he is the type of player our fans will enjoy watching perform."
- Sports & Recreation
- Dundee United
- Pat Fenlon