1. Woody Allen (he was a stand-up comic on the Ed Sullivan, Johnny Carson, Smothers Bros., Dick Cavett, Merv Griffin and Jack Paar shows and had acting parts in What's New, Pussycat? and Casino Royale before directing 1969's Take the Money and Run)
2. Sydney Pollack (he was a TV actor/director with parts on shows like Twilight Zone, Ben Casey, Alfred Hitchcock Presents and Have Gun - Will Travel, and he had a role opposite future collaborator Robert Redford in the 1962 film War Hunt before directing his first feature film, 1965's The Slender Thread)
3. John Cassavetes (he had roles in films like Crime in the Streets and Edge of the City before directing 1959's Shadows)
4. Gene Kelly (he was already a big movie musical star, with an Oscar nomination [Best Actor of 1945 - Anchors Aweigh] to his name before co-directing 1949's On the Town)
5. Elia Kazan (he was a Broadway performer in shows like Golden Boy and Liliom, and had a brief run as an actor on film in City for Conquest and Blues in the Night in the early 1940s before directing 1945's A Tree Grows in Brooklyn)
6. Rob Reiner (he was the son of TV legend Carl Reiner and an Emmy-winning actor, from his time on the classic sitcom All in the Family, before directing 1984's This Is Spinal Tap)
7. Tom McCarthy (he had supporting parts in the comedy films Meet the Parents and The Guru, and was a favorite of David E. Kelley's [who cast him in Boston Public, The Practice and Ally McBeal] before directing 2003's The Station Agent)
8. Clint Eastwood (he was already a western star with roles in TV's Rawhide and a bunch of Sergio Leone spaghetti westerns, as well as the little-seen Ginger Rogers/Carol Channing musical western The First Traveling Saleslady, before directing 1971's Play Misty for Me at the ripe old age of 41)
9. Sofia Coppola (the daughter of Oscar-winning filmmaker Francis Ford Coppola had bit parts in Rumble Fish and Peggy Sue Got Married before turning heads with her Razzie-worthy work in The Godfather: Part III and Star Wars: Episode I - The Phantom Menace, and certainly before changing our minds with her directorial debut, 1999's The Virgin Suicides)
10. Ron Howard (this former child actor of The Andy Griffith Show,The Music Man and The Courtship of Eddie's Father became a reputable teen/young-adult actor in films like American Graffiti and The Shootist [for which he earned a Golden Globe nomination] and on TV's Happy Days [for which he won a Golden Globe] before directing the 1977 Roger Corman-produced Grand Theft Auto)
Umm, of course. But this poll is meant to force people to think outside of the box of the usual suspects...
Think "outside the box of the usual suspects"? If anything, Clint Eastwood is the epitome of performer turned director. Ditto Woody Allen. Ditto Ron Howard.
As for Sofia Coppola, good thing she is a talented director, 'cause she was never going to be remembered for her 'acting.'
Anyway, since you insist on playing by your rules, I will vote for Rob Reiner. He's not the best director on your list, but I like him as a person. And I love WHEN HARRY MET SALLY and, especially, MISERY...
I'm a big fan of Peter Mullan's directorial work, as well as his acting. The Magdelene Sisters in particular was a haunting piece of filmmaking. It's just the type of film that creeps up on you the more you think about it. Orphans and NEDS are pretty great too. He delivered such an unneverving performance last year in Tyrannosaur as a vicious violent man and has had quite a prolific acting career since the 90's.
Three people that popped up right away in my mind: Barbra Streisand, Robert Redford and Todd Field. Among your 10 only Allen and Eastwood were successful enough on both areas, IMO, and Allen was as much a director and writer as an actor from day 1. So that leaves me with Clint Eastwood.