The 33-year-old left West Ham United earlier this summer as a free agent but has now completed a free transfer to The Blades, who were quick to snap him up before the transfer window shuts in just a few days time.
Ings last featured in the Championship for Burnley in the 2013/14 season, when he netted 21 goals and on signing for the Blades, Ings commented:
"I am delighted. It has been a busy few days. When I spoke to the manager and he asked me to come up and spend some time with him and the group, I just thought it was a great opportunity.
“To be sat here now speaking to you, and the Sheffield United fans, is just fantastic.
"As soon as I spoke to the manager, I wanted to get up here and sit down face-to-face and meet everybody here. To be sat here now and signed, it is really exciting.
"I've been keeping myself fit, and I've just been waiting for the right opportunity. I thought this was a great one for me and a chance to progress my career as well."
Sheffield United have seen defeat in all of their opening four games this season, and supporters will be hoping that Ings can bring his goals to a side who were tipped for promotion this season but are looking more likely to go down at the moment under manager Ruben Selles.