Ward was told he was surplus to requirements at the iPro Stadium by Steve McClaren and allowed to leave on a free transfer despite having a year to run on his contract.
The Northern Ireland international found himself out of favour with McClaren in the second half of this season following the loan arrivals of Tom Ince from Hull City and Jesse Lingard from Manchester United.
The news of Ward's availability on a free transfer has sparked a great deal of interest, with the 29-year-old a proven performer in the Championship.
Nottingham Forest are thought to be leading the chase for Ward as they are only able to sign free agents and loan players due to their transfer embargo.
However, Sheffield Wednesday are also keeping tabs on Ward as they weigh up a move for the former Sheffield United man to bolster their attacking options for next season.
Ward joined Derby from Sheffield United in 2011 and played 149 games, scoring 34 goals.