The 49-year-old, a lifelong Blades fan, has signed a two-and-a-half-year contract at Bramall Lane having left Port Vale after guiding them to second place in npower League Two this season.
Adams, who takes over from Gary Speed, has made former Blades striker Alan Cork his number two while caretaker manager John Carver and assistant manager Sam Ellis will be leaving the club.
Adams said: "There is no doubt my task is threefold. Firstly, to ensure we avoid relegation and there is clearly enough time left in the season to do that.
"Secondly, to help us become a team that can challenge for promotion. Lastly, to develop a structure that will see us build a reputation for home grown talent that fans can be proud of in their team.
"With the support of the board and the football staff, I intend to do everything I can to bring all that about."
Chief executive Trevor Birch said: "I am delighted to announce we have filled the managerial vacancy. Micky is a top-class appointment and the board were unanimous in the decision to endorse Micky in the post at the club."
Source: PA
Source: PA