A subject that came up in another thread.
I concluded that is it between Paul Verhoeven and Sergio Leone.
(Howard Hawks and Godard received honorary Oscars. If you worded the question a little differently – “The best director never nominated for an Oscar” – then Verhoeven and Leone are in a heated battle with Godard.)
Any others?
From the comments:
Brian De Palma could be added in the list. Rob Reiner would be on the list of having won one for producing A Few Good Men but he was never nominated for any others.
and
Terry Gilliam has one nomination for adapted screenplay, zero noms for directing
and
Bryan Singer?
and
John Carpenter
and
Hard to pick a single director but on a short list, I’d include Sergio Leone and Brian de Palma (and maybe John Frankenheimer). If non-directing Oscars/ noms don’t invalidate a person, I’d include Sam Peckinpah and Tim Burton.
—–
On the other side of the equation – Who is the worst director who was nominated for an Oscar?
I asked ChatGPT, and the response was:
If you want the harshest cinephile answer, the names most often mocked as “how did they get nominated?” are probably Stephen Daldry, Tom Hooper and Lee Daniels
I think that French dude who directed Emilia Perez should get some kind of special recognition for winning Best Director for a film rated 5.3 at IMDb.

Kurosawa got a directing Oscar nomination for Ran.
I forgot that one. Thanks.
Brian De Palma could be added in the list. Rob Reiner would be on the list of having won one for producing A Few Good Men but he was never nominated for any others.
Welles?
My bad. Welles was nominated
Finally something we can all agree on. Give that man his Oscar.
Bryan Singer, maybe.
Terry Gilliam has one nomination for adapted screenplay, zero noms for directing
John Carpenter
Hard to pick a single director but on a short list, I’d include Sergio Leone and Brian de Palma (and maybe John Frankenheimer). If non-directing Oscars/ noms don’t invalidate a person, I’d include Sam Peckinpah and Tim Burton.