The 32-year-old was released by West Brom in the summer and trained with Sheffield Wednesday, Blackpool and Chesterfield but to no avail.
He links up with another Forest old boy, Colin Calderwood, who took over the managerial reigns last month.
Lyttle, who regards his time with Forest as the best of his career, still enjoys golf at Stanton-On-The-Wolds in Nottingham and is looking forward to the challenge.
He said: "I live in Staffordshire so it's not too far away for me, it's a good set up and hopefully I can sign a longer contract,"