Alois Hitler, Jr. (nee Matzelsberger) (1882-1956), elder half-brother
Angela Hitler (1883-1949), elder half-sister
Four siblings died in infancy or early childhood of illnesses:
Gustav Hitler (May 15, 1885 - December 8, 1887 in Braunau am Inn), elder brother. According to old OSS files, it seems that Gustav was also the reason for the marriage of his parents, because Klara was already five months pregnant at that time. He died during an outbreak of diphtheria in 1886, along with his younger sister Ida.
Ida Hitler (September 25 1886 - January 2 1888 in Braunau am Inn), elder sister, died of diphtheria.
Otto Hitler (1887 in Vienna), elder brother, lived only 3 days.
Edmund Hitler (March 24 1894, Passau - February 2 1900, Leonding), younger brother, one of only three surviving children by 1900, died of measles.
Paula Hitler (1896-1960), younger sister and only full sibling to survive into adulthood
Geli Raubal (1908-1931), niece, daughter of Angela.
William Patrick Hitler (1911-1987), nephew, son of Alois Jr.
Heinz Hitler (1920-1942), nephew, son of Alois Jr. Captured and killed by the Red Army.