McCall held talks with his former club, where he ended his playing career and began coaching, but decided against a move to npower League One.
McCall, who signed a new two-year contract in March, said: "It has been a really difficult last few days. As most people probably know, I spent five great years at Sheffield United.
"I was grateful to the board for allowing me to speak to them but I went with an open mind. I had no desire to leave Motherwell after enjoying two-and-a-half great years at the club.
"There is no doubt Sheffield United are a fantastic club but, after careful consideration and deliberation, I am more than happy to continue my current role at Fir Park.
"I have built up a tremendous feeling for Motherwell, the people who work at the club and the supporters. It would take something really special to tempt me away."
McCall has led Motherwell to third and second place in the Clydesdale Bank Premier League during his two full seasons in charge and turned down the chance to speak the likes of Blackburn and Burnley last season.
His decision is a huge boost for Motherwell as they bid to persuade Michael Higdon, James McFadden, Chris Humphrey and Tom Hateley to sign new deals.