Ward made 12 appearances for Forest during an initial nine-week spell at the City Ground that came to an end after the Reds' 2-2 home draw against Crystal Palace on December 29 - Alex McLeish's first game in charge.
Forest chairman Fawaz Al Hasawi told the club's official website: "Elliott proved how valuable to our squad he can be during his initial loan spell with us.
"He made it clear he wanted to come back to the club for the remainder of the season and we're delighted to have him here."
The 27-year-old centre-half will go straight into McLeish's squad for Saturday's home Championship fixture against Peterborough.
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