Whing, who came through City's Academy and was the last professional player to score in a league match at Highfield Road, had been at Brighton & Hove Albion and back in October was loaned out to the East London club.
Brighton have agreed a settlement with Whing and he has signed for Leyton Orient until the end of the season.
Brighton's manger Gus Poyet said to his club's official website: "Whingy is a top professional, but with the players we have in the squad he has found it difficult to get into the team.
"We are pleased he has secured a new contract until the end of the season, and we wish him all the best at Leyton Orient."