How do we define the Golden Age? Wikipedia suggests up to 1959. If so I'd say with Miss De Havilland's passing Sidney Poitier and Sophia Loren may be the last two "great" stars to still be with us. Eva Marie Saint was a supporting actor mostly. Clint Eastwood didn't really become a star until the 1970's. Joanne Woodward began her career as a star but got much less prominent as the decades went by.
Jane Powell, Rhonda Fleming, Arlene Dahl were never "great" stars.
Angela Lansbury was never a "great" star of the screen, really, but definitely of theatre.
Even the child stars of the Golden Age- Mickey Rooney, Shirley Temple, Deanna Durbin- are gone. (Thank God that dear Jane Withers remains.)
And for supporting actors, the dean of them all is Norman Lloyd at 105!
They have been a tenacious lot, the Greatest Generation!