Wikipedia:WikiProject Harry Potter/OP Differences

These are differences between the book and film versions of Harry Potter and the Order of the Phoenix by J. K. Rowling. Because the film has not yet been released, much of this information is commentary and will change as the movie's production progresses.

Uncast status
There are some characters that are in Order of the Phoenix who have not and never been cast, and, if casting announcements remain as they are now, are cut from the film adaptation. They are (in order of appearance) Mundungus Fletcher(Whose role was cut), Mr. Prentice (Muggle resident of Little Whinging)(Whose role was cut), Elphias Doge, Hestia Jones, Emmeline Vance, Dedalus Diggle, Walburga Black (Sirius' mother), Bill Weasley (Who was played by richard fish in poa), Eric Munch, Perkins, students mentioned specifically by name by the Sorting Hat, Professor Binns, Peeves, Michael Corner, Terry Boot, Dennis Creevey, Marietta Edgecombe, Anthony Goldstein, Warrington, Montague, Theodore Nott, Phineas Nigellus Black, Dilys Derwent, Everard, Broderick Bode, Frank and Alice Longbottom, Miriam Strout, Augusta Longbottom, Madam Puddifoot, Augustus Rookwood, Fortescue, Griselda Marchbanks, Professor Tofty, Antonin Dolohov, Jugson, Mulciber, Avery, Rodolphus and Rabastan Lestrange, and Williamson (Auror).

Kreacher is confirmed to appear; however, no announcement regarding the casting of his voice has been made.

Additions
William Melling will return as the Gryffindor boy Nigel, who was invented for the fourth film.

Previously cast characters not returning
The following characters have roles in the book version and have appeared in previous films, but will not reprise their role. The character they play is either recast or cut.

Previously cast characters possibly returning
The following characters have roles in the book version, and have appeared in previous films, but did not reprise their role.