The Blades have paid a substantial undisclosed fee to secure the services of an experienced Championship defender, who also has played in the Premier League.
Previously of Fulham, Richard Stearman has put pen-to-paper on a three-year deal at Bramall Lane to become Chris Wilder's fifth summer signing.
The 29-year-old, who spent last season on-loan at hometown club Wolverhampton Wanderers, has also represented Leicester City and Ipswich Town.
Stearman brings a wealth of second tier experience to South Yorkshire, playing over 250 times in the Championship, whilst he earned several England caps at junior level right through to the U21s earlier in his career.
Of the arrival of the centre-half, who can also operate at right-back, boss Wilder remarked: "Richard was our number one target throughout the summer and I'm delighted he has signed. We've been on the look out for a central defender who has played extensively in the Championship and who possesses the qualities and characteristics to fit in with our group.
"Richard will undoubtedly strengthen us, he's a calm influence in the dressing room and every manager who I have spoken to about him says he has outstanding leadership qualities and will offer 100 per cent commitment, on and off the pitch.
"He had other opportunities to pursue, but I am delighted we have managed to tempt him to Bramall Lane."
Stearman joins Ched Evans, Nathan Thomas, Enda Stevens and George Baldock as the new arrivals at Bramall Lane this summer.