Chris Wilder’s replacement has been in charge for just six months.
Jokanovic, 53, became the Blades’ first overseas manager in May when installed as Chris Wilder’s permanent replacement.
The Serbian won promotion to the top flight with his previous English clubs Watford and Fulham, but has won only six of his 19 league games since taking over at Bramall Lane.
The Blades won their first league game in five on Tuesday night, 1-0 at Reading, and are eight points adrift of the play-off places.
Their hopes of an immediate return to the Premier League have been dwindling by the week, with Jokanovic’s side losing eight Championship matches.
Jokanovic signed a three-year deal to succeed Wilder, who had departed the previous March with the Blades lying bottom of the Premier League.
The club’s bid to bounce straight back has been hindered by injuries and they were dealt another blow on Tuesday night at Reading when John Fleck collapsed off the ball.
The Scotland international was given oxygen and left the field on a stretcher before spending the night in the Royal Berkshire Hospital. He has returned home and is currently being monitored.