The Blades have moved quickly in the January transfer window, bringing in Jamie Murphy from Motherwell for an undisclosed fee.
Murphy, equally comfortable on either wing or a central striker's role, has signed a three-and-a-half year contract at Bramall Lane. He joins Danny Higginbotham, who signed on New Year's Day.
Glasgow-born Murphy has been capped at both U19 and U21 level for Scotland and had made close to 200 appearances at Fir Park since making his Motherwell debut at the beginning of the 2006/07 season.
This season Murphy has been in excellent form in the SPL, scoring 11 times in 28 appearances for Stuart McCall's side, including five goals in his last five outings.
On recruiting Murphy, Blades boss Danny Wilson added: "We are absolutely delighted to have secured a deal to bring Jamie to Sheffield United because the lad is a real talent.
"He is quick, strong on the ball and a good runner in possession. He will put defenders on the back foot and will offer us great versatility in forward positions.
"Jamie has a real eye for goal and will give us that bit extra quality in the final third that we need to unlock some stubborn League One defences."
Murphy completed proceedings on his Blades deal after playing his final game for Motherwell, captaining the side in the SPL fixture against Celtic on Wednesday.