Winger Pennant made just two appearances for the Potters last season – both coming in August – and he spent three months of the campaign on loan with Wolves.
Midfielder Whitehead played 30 times for Stoke in 2012-13, but only 12 of those were Premier League starts.
Goalkeeper Carlo Nash, defender Matthew Upson, midfielders Rory Delap and Matthew Lund and striker Mamady Sidibe are the other players the Staffordshire outfit have confirmed are being let go with their contracts at an end.
Stoke┬áhave also announced that Dave Kemp, Mark O’Connor, Adrian Pennock, Paul Maxwell, Dave Kevan and Gerry Francis have left their roles on the coaching staff.
Mark Hughes was last month appointed as the new manager at the Britannia Stadium, succeeding Tony Pulis.