The former Middlesbrough, West Brom and Bradford boss replaces Neil Warnock, who resigned last week after seven and half years in charge at Bramall Lane.
Blades coach Brian Kidd has been named as Robson´s assistant manager.
© Copyright PA Sport Ltd 2007, All Rights Reserved.
Do YOU want to write for GiveMeSport? Get started today by signing-up and submitting an article HERE: https://www.givemesport.com/writeforgms