Collingwood's late summons was prompted after coach Duncan Fletcher and captain Michael Vaughan inspected the Edgbaston pitch before discussing the squad's make-up with the selectors.
"It has been well documented that Birmingham has experienced unusually large amounts of rainfall in the last few days and this has put the ground authorities under extreme pressure," England chairman of selectors David Graveney said in a statement.
"Having looked at the pitch, it has been decided to add Paul Collingwood to the squad so that England will have the maximum number of options available on match day."
Collingwood, a mainstay of England's one-day team, was initially overlooked for a Test recall despite hitting three centuries in a week for his county Durham.
Graveney said on Sunday that adding Collingwood to the squad would have "muddied the waters" and affected the balance of the side.
Vaughan's side trail the five-match series 1-0 after losing by 239 runs at Lord's.
Australia have won the last eight Ashes series.
Squad: Michael Vaughan (captain), Marcus Trescothick, Andrew Strauss, Ian Bell, Kevin Pietersen, Andrew Flintoff, Paul Collingwood, Geraint Jones, Ashley Giles, Simon Jones, Steve Harmison, Matthew Hoggard, Chris Tremlett.
