Hunt broke his ankle soon after joining Crystal Palace last summer and is yet to play for the Eagles, but returned from injury and spent the second half of last season on loan at Barnsley.
He has joined Stuart Pearce's side until January.
Hunt, who completed 60 minutes on his Forest debut in their friendly defeat to Rotherham, told the club's official website: "It's such a big club. I was delighted to get the deal over the line and to get started straight away was perfect for me.
"It was my first 60 minutes of pre-season and I felt quite fit. I'm just missing out on a little bit of football so I'm looking forward to getting more in before the start of the season.
"When I joined Crystal Palace I wanted to play in the Premier League. I haven't had a chance to do that yet but, if I'm only here for the first half of the season, I'd love to help Forest be as far up the table as possible before I leave in January."