The Redskins didn't disclose terms of the contract, but a source told ESPN on Sunday night that Hightower agreed to a one-year deal.
Hightower announced Sunday night he had decided to return to Washington through his Twitter account, tweeting, "I'm baaaaaaaack" and including a picture of him putting on a Redskins cap.
The 25-year-old Hightower, acquired by Washington in a 2011 trade with the Arizona Cardinals, started all five games he appeared in last season for the Redskins before tearing his ACL against the Carolina Panthers in October and missing the rest of the season.
He finished the season with 321 yards on 84 carries and a touchdown. He also had 10 receptions for 78 yards and the first touchdown reception of his career.
A fifth-round pick in the 2008 draft out of Richmond, Hightower spent three years with the Cardinals. For his career, he has rushed 523 times for 2,054 yards and 24 touchdowns, with 128 catches for 879 yards.
Information from The Associated Press was used in this report.