By SABC Sport
8th August 2024
The 21-year-old played 21 times for the Blades in the Premier League as they were relegated last season, having spent the previous campaign on loan at Derby in League One.
Osula began his career in the youth set-up of his hometown club Copenhagen before moving to South Yorkshire in 2018.
"It's a big club, a great club, so I'm very happy for the opportunity to join Newcastle United," he told the club's website.
"It's a great opportunity, and as soon as I heard about Newcastle's interest I knew I had to take the chance to join this club if it came.
"It has come and I'm really happy to be here."
Manager Eddie Howe said: "William is a talented young forward with all the attributes to be an exciting player for Newcastle United.
"We have watched his development closely and we are delighted to have the opportunity to work with him in this next step in his career."