Actress hasn't been approached about award
The late star is up for Best Supporting Actor for his role in Batman flick The Dark Knight.
But Michelle, 28, has no plans to accept the award if he wins in January.
‘There have been no conversations about Michelle Williams presenting or accepting an award having to do with Heath nor are there going to be,’ her rep tells Access Hollywood.
It is thought that either his dad Kim or the director of the The Dark Knight, Christopher Nolan, will step up instead.
Heath died on 28 January after an accidental overdose of prescription drugs at the age of 28.
He is up against Tom Cruise (Tropic Thunder); Robert Downey Jr (Tropic Thunder); Ralph Fiennes (The Duchess); and Philip Seymour Hoffman (Doubt).