The 19-year-old defender’s new contract runs through 2020 and he will spend the 2017-18 campaign with the Championship side, who won promotion from League One last season.
"Cameron is young, athletic and highly-rated by Tottenham and we're delighted we've been trusted to continue his development,” Sheffield United manager Chris Wilder told the club’s official website.
Carter-Vickers will be available for Sheffield United’s game against Derby County at the weekend. However, it should not be assumed Carter-Vickers will be given a starting role.
Wilder added: "He is a central defender with a good attitude and adds competition for places in that area. I like the way Tottenham play and it's clear that Cameron has the ability to be a very good player."
The defender has represented the United States at multiple youth levels, and has taken part in a pair of under-20 World Cups. He has not yet received his first full senior team cap.